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Problems with DNA profiles - continued

Problems with DNA profiles - continued

If you found this file in an archive then use keyword "nutteingy2" in a search engine to find an updated version or related pages.
Updated file November 2005
Articles posted to moderated Yahoo community group for forensic science personel starting 16 July 2003,title of thread "Problems with DNA Profiles" under my nom de guerre of Nona Revers or as it turns up there nonarevers.
Text in brown is my contribution - due to the nature of such dialogues the thread can get rather broken as it splits into different sub-themes at different times and involving different people. Yahoo forensic science group
A more searchable archive of that group
Subject: Problems with DNA profiles

The following like the first "y" file can get a bit jumbled, and probably sections missing, for anyone wanting the original question/reply structure then please consult the archives on http://infoarchive.net/sgroup/forensic-science/

Two questions on DNA profiles

A crime-scene profile has a full set of 13 loci so 26 data points. On 25 there is a perfect match with a profile on a database. The 26th allele from the crime is 18 but the database is 18.2 - is this declared a match ?

Second question concerning another crime-scene profile of a totally unknown/unwitnessed offender. Frequency analysis of the alleles indicates he is 50 times more likely to have ethnicity A than B. But one pair of alleles are extremely rare in A population say 0.002,0.002 but in population B it is say 0.015,0.15 . Do you declare no result or does one determination override the other ?. As equally rare for both alleles then it is difficult to argue mixed parentage from A and B populations.



On the first part, I don't think anyone would declare it a match without further examination. Even after further examination I still think they wouldn't use a term like that.

For your second question, I'm not aware of anyone in the US that uses the population databases to determine possible racial information.

On the first part a match should not be called, but the similarity between the crime scene profile and that of the person on the database would probably result in further tests, certainly at the locus in question. If these confirm the discrepancy then that person should be eliminated, but I would expect investigators to consider close relatives, especially twins of the same sex as the person on the database.



Ancestral background is just when it all starts getting interesting. I have been trying to establish whether D2S1338 alleles 17 to 20 relates to Anglo-Saxon (Germany ,Flemish,Saxony) background and 20 to 24 a Celtic (Welsh,Scottish,Irish) background for UK caucasians.

Just thought this piece worthy of airing here - Juror interpretation of CSI type television http://www.zwire.com/site/news.cfm? newsid=10059769&BRD=982&PAG=461&dept_id=467992&rfi=6

DNA profiling query

Would anyone care to put on a defence, expert-witness, hat and give an interpretation of this report from a recent UK court case ? In particular the possible nature of the 20th allele(s) referred to in verbatim/transcript quotation marks.

Quote Forensic scientist F S explained that what is known as SGM Plus testing looks at ten sites on strands of DNA to identify 20 'numbered components' which are compared to an identical test carried out on a suspect's DNA. If any single component does not match, then the two samples cannot have come from the same person, but if they do match, a statistical analysis is carried out on the odds against it having come from anyone else. In 1997 she initially carried out the SGM test which was used at the time on four of the internal swabs. But last year, before W had been arrested, she carried out the more advanced SGM Plus testing. Of the tests on vaginal swabs, Mrs S told the court: "There were 19 definite components out of 20. The 20th was present, but there was some uncertainty as to whether it was one of two different numbered components." After W's arrest she tested his DNA, and found the same 19 components plus a possible match to the one she had not been able to identify and there were no differences. She told T R QC, prosecuting, the chance of it being from someone else was one in one thousand million. End Quote

I forgot to say this rape and murder happened 7 years prior to the court case. DNA profile from the defendent on another matter, 6 years later, was the only evidential connection to the murder.

The only other, circumstantial, evidence was that he lied about ever having been to the crime-scene town. The prosecution showed he had an operation at the town's hospital the previous year. Also his ex-girlfriend originally gave him an alibi for the relevent night but she later retracted this.





I'm not really sure, since it is a bit out of context. I am sort of stretching here, but perhaps the 20th allele was at a level below their interpretational threshold and there was an artifact present at about the same level. The "20th" allele theoretically could have been one of the two peaks, but it was not certain which was which.

I really can't tell just from reading this, but this was my first guess.



My concern was if this was a possible interpretation of the statement as written. Assuming TWGDAM protocols etc observed and tests repeated. Also no indication that either sample was mixed. Could one sample have given a homozygotic ,say, (18,18) on one sample and a variant allele (18,18.2) at the same locus on the other sample. In other words a 19 point match/20 point mismatch which of course is a mismatch.

It is possible to have slightly different DNA profiles in different tissues, due to mutation. This would create a "19 point match and 20 point mismatch." Just because a person has the same DNA profile as the evidence, it doesn't necessarily mean that the person left the DNA there (it may be a billion times more likely to find the DNA types if left by him than another random male, but still a chance). Similarly, a slight mismatch doesn't mean that the person didn't leave the DNA. He may still be millions of times more likely to have left the stain. Basically you would find the probability of finding a person at random that matches all loci except for the one mismatch. Then you factor in the odds of a mutation at the mismatched locus. If the probability of finding a random male in the population with the matching alleles 1 in 1000 million and the probability of a mutation at the remaining locus is 1 in 1000, the overall probability would be about 1 in 1 million.

Taking a more general case. If we were to take both a blood sample and a buccal sample, say, from the same individual at the same time. Test both samples on know good, calibrated, equipment is there then a high probability of a match on 19 + mismatch on one ?

If this is a common occurance or any situation where there was an anomaly I would expect tests on different, say 5 loci. Ignore the anomolous one so match on 18 and it would have to be a match on all extra 5 loci or a mismatch declared.

Whatever the reason for the anomoly whether mutation within the given individual or known systemic failing. Such as known problem with FGA and SGM Plus, from Forensic Science International 112 (2000) 151 - 161 sometimes falsely recording say (19,26) as apparently homozygotic (19,19).



First of all let me state that my numbers were totally made up. I don't actually know the frequency of a mutation off the top of my head. I don't know the stats on a mutation like this, I've never encountered it. Paternity labs encounter this much more frequently. But the mutation rate is much higher in a given sperm (or egg) cell than in the totality of the semen.

Lets say for instance that a mutation happens at a given locus in 1 in a thousand sperm cells (numbers made up). Then a child of an alleged father has a decent chance to have one allele that doesn't appear to support paternity.

But if the SEMEN from the father is tested, 999 out of 1000 sperm cells may have the normal type, while 1 may have the mutant type. This mutation would go UNDETECTED in the semen, since it is swamped by the normal sperm cells.

Just as a mutation can happen in a given sperm cell, it could happen in a given blood or epithelial or any other cell. This would cause maybe one in a thousand cells of these types to have a mutant allele. This still might not be detected.

But suppose the first cell in the zygote, that would eventually divide and differentiate into the testes, has a mutation. Then all of the sperm cells that were created in the testes would show this mutation. This is much rarer than the mutation for any given sperm cell. I don't know what this number is, but someone probably has calculated this. My example of 1 in a thousand is much more common than this would be. It may be 1 in a million or 1 in a thousand million, I don't know.

Lets say for example that a mutation like this happens 1 in a million times: If the probability of selecting a person at random and finding a matching profile is 1 in a thousand million, then it is a thousand times more likely that the DNA would match if it was left by the DEFENDANT than a random male. If the probability of selecting a person at random and finding a matching profile is 1 in a thousand, it is a thousand times more likely to find the profile if it was left by a RANDOM MALE than if it was left by the defendant.

So to properly deal with a situation like this, you would need to take in the rarity of the DNA profile in the population and the rarity of a mutation event like this. If one is significantly more rare, it would sway the evidence.

If you simply went to the respective tissue (like obtaining a semen sample if the difference is in the semen) and it matched there, it would confirm the mutation and make this whole arguement moot.



I don't know about all labs, but I would guess that they would report it as a probable match, and give the appropriate statistics. I also think they would ask for a sample of the appropriate tissue. For instance if there was a difference between the blood and the semen, they might ask for a semen sample to confirm the mutation exists in the semen. It might be difficult to confirm the difference anyway. It is often easier to confirm that there are slight differences than to confirm how or why those differences might exist.



The 1 in a 1000 figure seems to be regularly quoted in the paternity testing area. This relates to first mitosis at oogenesis where a mutation, of 1 allele, goes on to produce a mismatch in all the cells of the blood (say), between parents and offspring. The process of evolution requires it for survival of succesful variants and suppression of non-viable variants, for advancement of the species. There is probably the same process in later mitosis, at the stem-cell stage, where just one organ or cell-line could vary from the rest of the body. Anything later and there would be an infinity of possible sports, not all the same variant. There is a minimum of, 200 or so, cells to pass through the normal PCR process.

An un-explained, just posited, tissue mismatch would be fine in an academic study but this was presented in a murder case where the defendent was given a life sentence. It is absolutely beholden on the prosecution to exactly explain this 20th mismatch - to the extent of analysing different tissues of the defendent. Posing a prosecution view (accepting the,20 point, billion:1 figure for the moment) then 19 point match <>350million:1 false match figure shoots past the 1billion to an off the planet 1000x 350m:1, if the defendent has a proven mismatch on this 20th allele between semen and buccal cells. Taking the defense view (if they had had a DNA expert), failing to nail down the 20th mismatch, the prosecution has presented evidence of exclusion,not inclusion. 19 point match + 1 point mismatch is a mismatch - not a match. They cannot take the best of 20 to declare a match, it is all or nothing.

If I had been in the public gallery of that courtroom I would have been shouting - foul !

Much thanks for the input on this very technical point but so far I've seen nothing to sway me from my original assessment that this was a highly unsafe conviction. The other 'evidence' was a very murky night-time CCTV tape that showed a human form and certainly no points as to identity. The defendent lied (understandably) that he had visited, at any time, this town 25 miles from where he lived. He was proven to have had a specialist operation at this town's hospital. His ex-girlfriend changed her testimony, not giving him an alibi, as to where he was that night 7 years previously.

Misrepresenting statistics - what does it mean?



The most recent information coming out of the HPD lab scandal (see: http://www.chron.com/content/chronicle/special/03/crimelab/index.html) is that their forensic scientists have given inaccurate statistics and insufficient evidence in 23% of the cases reviewed. It's the inaccurate statistics thing that's bugging me. I've seen forensic scientists misrepresenting numbers, overstating the confidence of evidence, say match to a jury without explaining what it means and know damn well the consequences... This is also akin to what Joyce Gilchrist of Oklahoma and Arnold Melnikoff of Montana and Washington State were doing - lying about the numbers and in some cases citing phony statistics. These were not and are not stupid people working in isolation from the rest of the forensic community. And they've all been doing it for a long time. And they've been promoted and rewarded for their work by others. It's not possible that those at HPD and that Gilchrist and Melnikoff and the many others like them are doing this without the knowledge of other forensic scientists. Is it? The first question then is this: Is this malice or ignorance? Do these forensic scientists and those who've trained them simply not understand the basics of hair and DNA analysis? Is that possible? Because I've read some Saferstein I've always assumed that this kind of conduct was malice... but that assumption may be misplaced if this problem is so widespread. The second question is this: what would the results be if similar independent evidence/ testimony audits were conducted of other state crime labs? Question # 2 should be of concern to every young or student forensic scientist out there whose working or considering work at a state police lab. The lesson of the Huston PD crime lab is that this kind of stuff only stays under water for so long. Eventually, it comes to the surface and then everyone whose taken a drink from the pool is a suspected carrier. I would sincerely appreciate any public or private response to these questions. I'd just like to know what other forensic scientists think.



They are all doing it not just HPD

If you look for the statistics used as the backbone behind DNA profiling you find reams of theory but no simulations or extracted from real data. I've hunted through all the relevent forensic science journals and its all theory leading to the 1 in a billion through 1 in 100 billion through to trillions and even quadrillions quoted as fact in court.

I know from my own simulations based on the published allele frequencies that multi-billion figures are criminally false. The figure for 10 loci SGM+ as used in the UK for a 2 million database has to be less than 1 in 1.8 million chance of false matches.

I would say in Gilchrist's case, it was malicious, but I think in Houston's case it is more of incompetence.

Most of Houston's problems came with mixture interpretation and how the statistics relating to mixture interpretation are understood and presented.

Here is a somewhat simplified scenario to illustrate what was going on: Lets say that at a given locus there are three possible alleles: A, B and C. Each person has two alleles, so there are six possibilities (AA, AB, AC, BB, BC, and CC). But AA, BB and CC are only observed as A, B and C. Let's say the defendant is AA. Lets also say that only 1% of people have AA at this locus. But lets say that the EVIDENCE sample is a mixture and happens to type as ABC. In this case, you cannot tell how many people are contributing to the mixture. All six possible genotypes are included in the mixture. So the defendant is included in the mixture, but so is EVERYBODY.

Houston reports that the defendant is included in the mixture and that the probability of selecting a person at random THAT HAS THE SAME GENOTYPE AS THE DEFENDANT is 1 in 100.

The competent lab reports that the defendant is included in the mixture and that the probability of selecting a person at random THAT WOULD BE INCLUDED IN THE MIXTURE is 100 in 100.

It doesn't matter what the probability of having the same genotype as the defendant, we only care how likely someone would be included in the EVIDENCE. But these can be very different.

Thanks for responding with this excellent and very clear example.

Given that this is such a basic thing, and that the error is an accurate display of statistics that are pro-prosecution but unrelated to the specific circumstances of the evidence in a given case (and a failure to explain that everyone, not just the defendant, is included as a possibile contributor) --- is this really just incompetence?

Presenting one set of favorable findings and witholding unfavorable findings seems incompetent, yes, and more han a little biased, yes. Could it be intentional but not malicious? Could it be that these paricular criminalists are so entrenched in the idea that they are "out to get the bad guys" that they have forgotten that they are supposed to be scientists?

By the way, thanks all for being patient with my questions.

It's just that my experience has taught me that there are very few people who wake up in the morning and think about how they are going to lie to keep the bad guys behind bars. Most people who do this kind of thing have simply convinced themselves that this is good science, or do not have the education or training to know that it isn't.

Personally I don't know for certain, but I think they were not intentionally giving statistics for purpose of helping the prosecution. They certainly may have been, but unlike with Gilchrist, I have never heard of them saying things like "the prosecutors love me because they can count on a prosecution..." as she supposedly said.

If they knew what statistics they should be presenting, but presented other stats, they were certainly malicious. But I sort of think they just didn't know what stats they were supposed to be presenting.

I thought coursework in statistics and probability was a standard requirement for any position involving genetic analysis. I've always been alarmed at the number of my coworkers who seemingly didn't understand the limitations of the technology they were using but unfortunately I can't say that I'm surprised anymore.

In clinical trial situations, use of accession numbers to identify specimens is standard practice (i.e.: double blind studies). Is this practised in forensic laboratories?



Actually you are totally off base. I have seen your models, they show a clear misunderstanding of the statistics involved.





But I deliberately do not involve statistics. I have a healthy disrespect for statistics and leave that nonsense to the Weirs,Budwoles and Baldings of this world. I am happy to use published allele frequency tables as they are derrived from the real world. On the latest dnas5.htm version, all alleles for UK caucasians are included which was the previous criticism. Otherwise the only straying into statistics is multi-modal matching and the broadening and sharpening of tail-offs of the otherwise approximated multi-Gaussian distributions. This is a consequence from doing such simulations - unknown otherwise, as I've found no reference to it in the DNA profile statistical texts. Summarised as - the commonest alleles increase in frequency in matches, rare alleles decrease in frequency , and rarest alleles are practically absent from matches. At least at the level of a 4 million pool. The square law is known within statistics and I have an explanation of it and it comes through in these simulations so no problem there. Summarised as - if you have x matches in a pool of y profiles then in 2y profiles you will have x^2 matches.

forensic scientists and dyslexia

i just wondered what the position is with forensic scientists (in the uk) with dyslexia ie can they still work or do they need a certificate to state this fact? thanks



The following errors ( one is architypal dyslexic w<>m nowhere near each other as keys on a keyboard ) in one of the standard forms from the principal UK FSS centre in Birmingham

" The details will only be used, however, for the for the (sic) prevention and detection of crime "

" consequently some of the following items may have no data recorded against them if it is not appropriate for the purpose for which the record mas(sic) made. "

1 of the 10 loci used in the UK, D8S1179 , was printed on this form as D6S502 not even the correct chromosome.

All undersigned by the then director a P. E. Cage

-----------

ps No one explained why my use of statistics was flawed in a post here a few weeks back.

Test for ex-frozen biological material ?

Are biological stains routinely tested for whether the serological material has been previously frozen? Is there a test for previous freezing, if their is suspicion of such a likelihood?

Hypothetical scenario - habitual rapist goes to area where prostitutes do their business. He picks up recently discarded condoms and puts them in his freezer. Later when committing a rape, using a condom himself, he deliberately spills the contents of one of his un-frozen condoms on the victim's clothing.

That's a very clever MO. I have heard that freezing produces crystals in flesh cells, like muscle, which tend to burst cell walls. I have never heard that it has done so in semen. I ran across some studies in the freezing of semen in prize animals (bulls-horses-dogs) that show decreased mobility in frozen-thawed semen, even with a preserving chemical. The thing is that crime scene semen is typically collected, dried, then sent to the crime lab, and then processed for typing. This is usually weeks after collection and the lab might even freeze it to preserve the stains, especially if case work it backlogged. And, In these days of DNA testing, where serological testing is almost never done, I doubt if the physical signs of freezing would be noticed at the lab, in most circumstances. So unless there was some hint of the MO with the discarded condoms, I doubt if it would ever come up. Detectives might scope it out, if the stain recovered resulted in a CODIS hit, and the guy with the matching profile had an ironclad alibi, like he was in jail, at the time of the crime. Also the dicks would get suspicious (I hope) if a series of similar rape investigation resulted in several different DNA profiles, unless he kept re-freezing and thawing the same condom, which would show increasing physical damage to the sperm. Kind of a goofy answer, but I hope it helps.

Homozygosity in DNA profiles

Contrary to my usual investigations my recent has gone counter to expectations. It is not the case, as generally perceived, that excess homozygosity would lead to greater likelihood of false DNA profile matches ( in autochthonous communities for instance). In fact the opposite is more likely.

Analysis:

I did 4 off 50,000 runs of 6- loci profiles based on Australian data. First run produced 64 off 12 digit matches. Adding some homozygosity, resorting and checking again there was only 50 matches. Another run , without excess HZ, produced 55 matches Repeating but this time adding the homozygosity at generation, sorting and match checking, again resulted in only 50 pairs.

Australian caucasian data just for locus D5 
Code here / Allele / Allele frequency %
0	8	0.49
1	9	3.08
2	10	6.03
3	11	39.16
4	12	34.36
5	13	15.64
6	14	1.11
7	15	0.12

For unmodified D5 subset of 50,000 profiles bi-allele totals, firstly homoZ then largest heteroZ counts 00 - 2 11 - 59 22 - 166 33 - 7,647 44 - 5,848 55 - 1,274 66 - 4

34 - 13,364 35 - 6,165 45 - 5,367 23 - 2,357 24 - 2,132

Then adding HZ, seriously over-inflating the rarest allele occurances 00 - 86 11 - 562 22 - 1,104 33 - 10,946 44 - 6,797 55 - 1,300 66 - 4

34 - 11,184 35 - 5,130 45 - 4,482 23 - 1,937 24 - 1,781

Overall excess D5 HZ = 38.7 % 33 excess HZ 43% 44 excess HZ 21.8% So new 33 count is now nearly the same as the now reduced 34 count and as a consequence is equally likely to influence the 6 loci match situation but only if the excess HZ on other loci is similar in behaviour. But if 33 excess HZ was only 20% then 33 count goes up from 7,647 to about 9,200 but still less than the 34 count now about 12,400. The square law has it that the larger counts predominate disproportionately.

Consider 44 situation ( less likely to occur in matches) but now 6,797 >> 4,482 so critical in comparison.

Now consider the general case. h is excess homozygosity expressed as scaling factor ie 1.28 rather than 28 per cent. a is the allele frequency of an alelle that has excess HZ factor of h and b is the highest (no excess HZ ) allele frequency of the remaining alleles. Normal HZ is a^2 and b^2 Highest normal hetero-bi-allele frequency = 2*a*b Excess HZ increases a to (a^2)*h Highest hetero-bi-allele frequency becomes approximately = 2*b *{a - 0.5*a(h-1)} = a* b*(3 - h) So criticality is if a*a*h <> a*b *(3-h) or a*h <> b* (3-h)

So even if h is high then the b frequency if high enough in comparison it can over-ride.
Then this effect has to be present in most loci to affect the overall match probability.

Excess HZ of less than 10 % is generally more likely to reduce the number of unrelated profile matches in populations of the same type and size

DNA profile error rate now down to 8 per cent

That is 8 in 100 forensic DNA profiles as used in the UK consisting of 10 markers and 20 datapoints. Most recent data from journal article International Journal of Legal Medicine (2004 ) Issue 2 118: p83-89 http://springerlink.metapress.com/app/home/contribution.asp? wasp=43wrc2wrrncvtvcg9j4k&referrer=parent&backto=issue,4,13;journal,3, 47;linkingpublicationresults,1:101167,1 or http://tinyurl.com/2t484 The GEDNAP blind trial concept part 2. Latest data for year 2002 which is an improvement 2001, 10 per cent erroneous profiles. 2000 , 14 per cent erroneous profiles. This data is anonymised so the good and bad are lumped together - considering the bad do not know they are bad (or at best, in disagreement with the consensus).

These are the results of GEDNAP ( German DNA Profiling Group ) blind trials of testing samples at 136 labs in 31 European countries.

First thing to note this was blind trial ( not double blind ) so all participants knew in advance and could process immefiately after calibration, not Friday afternoon processing / interpretation/ transciption etc.

Much of the 'improvement' is because: Many incorrect results in previous GEDNAP trials had been due to specific types of body-fluid stains so those "have since been discontinued because of the inconsistency of the amount of DNA present " from the more recent trials, despite those sorts of stains being commonly found forensically. Then the intractable human error:- "most of the errors were made each time by a very few number of laboratories and of course compound errors such as interchange of two samples caused a disproportionate number of errors relative to the one mistake made when sampling the wrong test stain. However, this is not taken into consideration when calculating the error rate." ( these specific errors included or excluded in the calculated error rate? )

"the most common type of error has always been transcriptional errors followed by incorrect interpretation due to failing to recognise an eror, these types of human error are to some extent unavoidable under any prevailing circumstances."

I repeat this is results from labs knowing they were being tested and presumably on their best behaviour.

Then the more technical/ systemic problems producing mistyping because of stutter, 'long alleles', unrecognised rare alleles etc.

19 correct out of 20 datapoints is fine in 8 out of 100 DNA profiles if you are identifying body parts, say, from a small pool of possibles but not for the usual forensic purposes of implied uniqueness.

I'm at the moment processing 10 million simulated profiles generated to CODIS 13 loci form and N. American Caucasian allele frequencies and all profiles generated totally randomly. Whether 10 million is enough to show at least one false match I don't know. Indicative info is that because of the rather ridiculous TPOX allele 8 in CODIS (2 chances of 54% for each person to inherit allele 8 ) means for these purposes CODIS is little more than 12 loci in effect. Australian NIFS 9 loci simulation gives a baseline population of about 400,000 ( on dnas9.htm URL below ) and UK , FSS 10 loci simulation gives 1.1 million (file dnas5.htm on URL below). CODIS simulation result will be file dnas11.htm , probably next weekend , ( flavour of what is entailed it requires about 1.5 GB of free disk space for processing ).

DNA Evidence

I have seen this brought up a number of times which leaves me with 1 question can a person be convicted in the UK on DNA alone ?

In Canada a person may be detained and questioned with the possibly of being arrested based on the presence of DNA, but for a conviction you would need more than just the presence of DNA.

As with any Database complete uniqueness seldom exists, for example in 1998 in Lethbridge Alberta a store was robbed and the clerk was shot. A camera from a neighboring bank filmed a 1967 - 1969 (The camera didn't catch the headlights so they couldn't be more accurate) Mustang leaving the scene. The vehicle had an Alberta license plate. There were 7 vehicles matching that description. I had a 1968 mustang registered at the time I was picked up for questioning after a few RCMP questions I was given a ride back to work and never heard from them again. So I don't see why complete uniqueness is such a big issue.

This is how I understand it. 4 people enter a building the criminal left some DNA behind. Out of those 4 people 1 persons DNA matches the sample at the scene the other 3 don't. So the DNA would exclude 3 people.





What is truth ? This article in one of today's UK papers http://www.guardian.co.uk/life/farout/story/0,13028,1225015,00.html Recounts an experiment first done in the 50s but still relevant. Forensic scientists can act as sheep or be deluded or just act under peer pressure like anyone else.

Why else would they believe what forensic statisticians say with only theoretical backing about probabilities of false matches with DNA profiles. ? Still outrageous figures eg 640,000,000,000 in Oz this week, are quoted with absolutely no empirical foundation. You could not get away with it in any other 'scientific' discipline.

As the authorities in charge of these large DNA databases are not divulging how many unrelated matches are contained within the arrestee side then I had to go out and simulate one myself to find out. As far as I can tell no-one else has done this ( or at least published the results )

Details of a full allele 2 million 'profile' computer simulation http://www.nutteing2.freeservers.com/dnas5.htm

It is my understanding that this group is a professional group related to the use of science in matters of law. From the posts I have read it appears many of the listees are students of forensic science. As forensic scientists, your duty does involve debate. However, this debate must be based upon scientific principles, not emotion, loyalty or politics. I am extremely disappointed in the latest political thread. As forensic practitioners your RESPONSIBILTY is truth. Truth based upon the physical and unemotional analysis of evidence. The fact that someone saw a photograph does not constitute the analysis of evidence. More importantly, the input of faith or political affiliation should never play a part in your unbiased observations or opinions. If voicing your political, religious or other non-scientific views is your interpretation of forensic science, then you have failed as a forensic scientist.

Which planet breeds forensic serologists ?

http://www.presstelegram.com/Stories/0,1413,204~21474~2300828,00.html Article Published: Wednesday, July 28, 2004 - 8:35:45 PM PST Quote When analyzing DNA, forensics experts tend to talk about numbers rarely heard outside college classrooms and science laboratories. They use terms like quintillions (a number with 18 zeros), sextillions (21 zeros) and septillions (24 zeros). And when it comes to matching DNA profiles, each zero matters. In the case of Mark Wayne Rathbun - the alleged Belmont Shore rapist - forensic serologist Thomas Fedor has calculated a chance of one in 844 septillion that someone other than Rathbun left his DNA on the left breast of victim Jane Doe No. 2 in May 1998.

But how did he get that number?

Such complex calculations, Fedor said, are based primarily on a population survey that indicates how many people in a group are likely to have the same information stored in their genetic markers.

For instance, Fedor said, if one in five people have the same information stored in one specific marker, then there's a 5épercent chance that two given people share that marker. If one in 10 people have another specific marker, then the percentage of people who share both these markers is calculated by taking 10 percent of 5 percent.

The calculation is simply repeated for each of the markers studied, Fedor said.

"If you take 10 percent of 10 percent of 10 percent of 10 percent 13 times, you're coming up with a very small number," he said.

This formula, Fedor said, is called the Product Rule and is widely accepted in DNA analysis.

Old Cases Involving Faulty DNA Testing Targeted - Texas

It does not require corruption - just blind faith in a very flakey technology, only 8 per cent of 10 loci DNA profiles are correct , Source: International Journal of Legal Medicine (2004 ) 118: p83-89. That is crime-scene or arrestee profiles. And slavish following of forensic statisticians.

Throughout the 1990s they were spouting, even in court , false match probability of 1 in 37 million for 6 loci profiles. That was until admission of a crime-scene profile matching 2 separate unrelated arrestee profiles in the (UK) NDNAD (R v. Watters appeal) and case of Raymond Easton forced a halt to that dangerous nonsense. The real 6 loci false match data for a population of 4 million is between 94,000 and 380,000 matches.

So they upped it to 10 loci which certainly improves things but not the multi-billion figures now spouted. Again for a 4 million population the false match figure is between 5 and 32 pairs. 5 is unrealistically low ( parthonogenic - no coancestry ) and 32 too high as all having similar ancestry as myself - one parent and his parents from one English county and mother and her parents from another English county ).

Because the technology is so flakey it is necessary to consider 19 out of 20 matches as a match not a mis-match. This is argued permissable because a mutation on any locus/ allele is possible (0.01 to 0.3 percent on any of the 20 loci/alleles) As long as further exploration to confirm this conjectured mutation - but do they ? 19 out of 20 if identifying identity of a decomposed body, profile already known, or someone named as a suspect in an enquiry but not where the suspect has been implicated from a DNA database trawl.

By 19 out of 20 I mean any 9 pairs matching and one allele match between the remaining pairs.

For the completely artificial situation for totally random profiles ( no co-ancestry at all ) then for any 19 in 20 then about 120 matches in 4 million or 1 in 33,000.

For the opposite situation and excessive co-ancestry then 28,000 free 19 from 20 matches or 1 in 140 of a 4 million population.

Until real-life data becomes available for co-ancestry ( parents & grandparents from same or different country, from same or different county etc ) tabulated against allele frequency minima then these are the outer bounds as it stands.

They only arrest the first person who happens to match in a DNA database, they don't wait for ten years, say, for a third match to come along.

Relevant simulations and results are on dnas5.htm and dnas6.htm on URL below. I would like to be able to point to academics or forensic scientists who have done such simulations but I seem to be the only one to determine false-match likelihoods from real-world allele frequencies. Afterall it does not require any fancy high-power computer

The USA with 13 loci CODIS profiles cannot be smug as one of there loci/alleles is TPOX (8) which 79 percent of people have one or more. Also increase the number of loci and you increase the chance of an error in any one locus/allele so throwing out the whole profile, falsely implicating or falsely eliminating.

DNA in the Dock

A Codis, 13 loci , 26 number unrelated false match. What about all the others without such a cast-iron alibi ?

http://www.suntimes.com/output/news/cst-nws-dna01.html Quote DNA links crime to woman with alibi -- she was in jail November 1, 2004

BY FRANK MAIN AND ANNIE SWEENEY Crime Reporters Advertisement

At first, police thought blood taken from the scene of a North Side burglary solved the crime because of a DNA match linked to a woman's genetic profile.

But it turned out the woman had a solid alibi: She was in prison at the time of the break-in about two years ago, authorities said.

Now, police are working with state officials to see whether there was a breakdown in the steps leading to the woman's DNA profile being entered into the database, known as CODIS for Combined DNA Index System.

Investigators are checking whether the state prison system mistakenly put the woman's name on another inmate's DNA sample. The woman submitted a mouth swab to state prison officials in May when she was paroled on a drug conviction, sources said.

Investigators also are looking into the possibility of the Illinois State Police crime laboratory entering the wrong information into CODIS.

There are other possible explanations, as well.

Robert Hovey, supervisor of the DNA Review Unit of the Cook County state's attorney's office, said investigators must make sure the blood sample was directly related to the burglary and that the woman was never inside the apartment. He cautioned against a rush to any kind of judgment about the system.

"We don't know if the bloodstain is related to the burglary," said Hovey, who did not know the details of the case. "But DNA is only going to prove presence. It is not necessarily going to prove someone committed a crime."

Lincoln Hampton, a State Police spokesman, said the state lab was looking into the case.

"They are reviewing that case and will present their findings to the Chicago Police," he said.

The burglary in the 1300 block of West Eddy was among a pattern of about 70 break-ins that police have been investigating.

The case intrigued Kathleen Zellner, a Naperville attorney whose work led to the exoneration of four men in the 1986 rape and killing of medical student Lori Roscetti. Zellner sought DNA tests that excluded the men as sources of semen on Roscetti. Two other men were charged.

"DNA has been the gold standard of evidence," Zellner said. "If you're implicated, you're sunk, and if you're exonerated, you're home free. But there are bound to be mistakes. I don't know of anything quite like this."

End Quote

30 year-old DNA

I keep reading of cold case prosecutions from recovered DNA profile evidence from 20 or 30 year-old evidence. I've searched FSI and IJLM for validation checks studies on the long-term stability of DNA and nothing found. These old samples are usually stored at ambient temperatures, not frozen. Frozen is the choice for current samples specifically for DNA analysis so obviously a preferred state. Degradation at room temperature leading to reduced number of loci being copied/identified but is there increased stutter or mis-interpretation of those loci that are identifiable.

Anyone know of any validation experiments in this area ?

Mixed sample DNA profile analysis - art or science ?

or artifice. I'm looking at a 2003 published journal report concerning analysis of a mixed sample. Unusually suspect as major components and victim as minor. Suspect was an employee and presumably prosecuted for rape. Analysis with Powerflex profiling so 15loci + 1 . Electropherograms of mixed stains, and referenece samples from suspect and victim are shown. With standard threshold setting of 150 units shows 11 alleles consistent with the victim and one vWA (14) that is alien to suspect and victim. Only 2 persons concerned in this sample, going by the maximum number of any allleles. Unmistakable peak well above threshold level shown in the plot but not apparently labelled as 14 - (tippexed out before publication ? ) There should ideally be 18 alleles from the victim so they lowered the threshold to 50 units and this brought up to 18. This plot is not shown in the publication , surprise , surprise. The >150 plot shows traces of the missing 7 but also 2 other alleles that must be >50 but alien to victim and suspect. A medical anomoly (trisomy ) concerning the victim was explained but nothing about this vWA (14) or the other unwanted 2 as spontaneous mutation or anything.



A low resolution pdf of this journal article is on http://www.cmj.hr/2003/4403/18DROBNIC.pdf Croatian Medical Journal 44(3) :p150 - 154, 2003 The British Library photocopy of the printed version of this article is slighly clearer but not much. The highly questionable spikes are evident in both PDF and printed versions. On page 351 on the bottom row , section B, two blocks of spikes from left, are spikes labeled 15,16 and 17 but to the left of them is definitely an unlabelled spike at position 14. The following will need magnifying the pdf.
The 3 lines of this B plot , including arrowed sites are
D3, THO1, D21, D18, Penta E
D5, D13, D7, D16, CSF, Penta D
XY, vWA, D8, TPOX, FGA


The extra spikes greater than the 50 threshold that are not arrowed would be D21 (29) [ third set on top row ] and D5 (10) [ first set of middle row ] and probably numerous others.

There is at least one unlablelled spike in the SGM 'A' plot of D19 (13) first in bottom row but all this 'A' plot are indistinct in this plot, again exclusionary

This vWA(14) on its own in a just world should have been exculpatory let alone the other alleles that had to pulled out of the mush - the reason for threshold limits as far as I am aware.

As silence so far and exploring other such cases I get the impression this behaviour of cover-up of such anomalies to be the norm in this area of forensic 'science'.



Can anyone give some examples of the use of mathematics in forensic? What kind of mathematics used? Is it calculus? Probability? Etc? Regards,

For anyone confused by this followup , it refers to journal article http://www.cmj.hr/2003/4403/18DROBNIC.pdf and thread (archived on NNY) from mid Nov , 2004 http://archive.nnytech.net/sgroup/FORENSIC-SCIENCE/3321/ http://archive.nnytech.net/sgroup/FORENSIC-SCIENCE/3401/

I take your point but in this article IMHO there is the most blatent of litteral cover-ups. The machinery & software automatically labels all alleles of peaks above a certain threshold. The peak '14' definitely appeared in the plot but the label has been deliberately removed and no reference to it in the text either.

I thought, until getting involved with forensic scientists, above all else scientists explore anomalies - it is absolutely fundamental to the scientific ethic. The trisomy was addressed for example.

My more general point about trying to pull incriminating data out of the mush below the threshold level has not been addressed. I have since obtained a photocopy of the printed version of this article and my observations are even clearer in the printed version than the low res pdf.

Let me break the unbearable "cover-up" silence.

First, have you ever heard of stutter? The vWA loci commonly experiences this artifact of amplification. Hence what you consider a 14 allele is probably a stutter peak. Notice I said probably. I would not be so foolish as to make any kind of definite assertion (such as yourself) based on the limited data presented in said article. Without the raw data for analysis no reasonable conclusion can be drawn from the Figure 1B plot.

Second, let's assume your assumption of a 14 allele at vWA is correct for the moment. The presence of the extra allele in a mixed stain is not exculpatory. This is elementary. Again, assuming the 14 allel was a legitimate peak, its presence would only indicate a possible 3rd contibutor to the stain. Extra alleles do not exclude contibutors from a mixed stain.

Sorry to destroy the shooter on the grassy knoll... no conspiracy here!

Re: vWA For forensic purposes ( false inclusion and false exclusion) vWA is highly suspect for the reason you state. Doubly so, because it is the worst for false homozygosities see FSI 143 (2004) 47-52 vWA and from this journal article D8S1179, FGA, D5S818 and D18S51 should be removed from multiplex analyses for forensic purposes, far too high occurance of false homozygosities. Only picked up like this cmj case study by splitting samples and running on different systems, primers etc.

Let me break the unbearable "cover-up" silence.

First, have you ever heard of stutter? The vWA loci commonly experiences this artifact of amplification. Hence what you consider

If you really believe your statement about "proper" science not requiring interpretation, then you have little true understanding of the scientific process and its application.

_ALL_ scientific data requires interpretation by a human scientist in order to draw conclusions about it. Computers and analytical instruments only produce data, they can't interpret it. They are idiot savants - great number crunchers but unable to interpret and apply their products. They can't recognize relationships and draw conclusions on their own. They only know and understand relationships that human beings define for them. Until artificial intelligence is perfected to the point where it can duplicate the synthesis of new information and recognition of subtle connections between seemingly unrelated data that human minds routinely accomplish, the GIGO (Garbage In, Garbage Out) principle applies. Computers can suggest inclusions or eliminations, but only human experts can differentiate those suggestions and confirm which is correct.

No result produced by a scientific instrument or process should be accepted without scrutiny and evaluation by a human expert. Anyone who would trust a machine to draw scientific conclusions for them is a fool destined for disaster. It takes a human being with appropriate expertise to decide whether or not the data that instruments and computers produce is even valid, let alone to determine how to apply and interpret it. Your "dispassionate filters" are figments of imagination that will never have the necessary intelligence and insight to do what you seek, unless cybernetics can one day produce a true artificial mind with a consciousness all its own. We are still quite far from turning such science fiction into reality.

Regarding your last comment with its slanderous insinuation, please listen up. Reputable forensic scientists, like all reputable scientists, work for one thing and one thing only: the discovery, documentation, and revelation of scientific facts. We don't care what direction those facts lead; we will accurately characterize and report them regardless of who they help or hurt. We don't work "for" the police, the prosecution, _or_ the defense, and our conclusions aren't influenced by who pays our salaries or "commissions" our work; nor are our careers influenced by whether or not our results are what our "customers" were looking for (our careers are influenced only by the quality of our work). We "tell it like it is," and let the chips fall where they may as it is no concern of ours. We are not partisans within the adversarial system, and have no stake in how cases are ultimately adjudicated.

We are simply fact-finders with no goal or end to achieve other than the presentation of those facts to the investigators, attorneys, judges and juries; it is THEIR jobs to determine the case outcome, not ours. Any among us who allow themselves to become prejudicially influenced by ANY part of the criminal or civil justice system only disgrace themselves and are justly pilloried and expelled from our profession.

The goals and desires of legal advocates are irrelevant and of no consequence to us or our work, other than to advise us of the questions that need to be answered in a given case. Any police investigator, prosecutor or defense attorney who tried to influence our work product or our report content would be bluntly told to go pound sand. None has ever dared to suggest such a thing to me more than once, I can assure you. Objectivity and impartiality are the very basis of this or any science, and we of the forensic science profession guard ours particularly zealously.

Are we clear now?



Thank you for taking timeout to read the report and reply in full and on theme rather than discussing extraneous matters.

vWA (14) is a perfectly valid naturally occuring allele , it can also result erroneously in a plot, from stutter. By what automatic process, on one pass through the system and one set of primers, can recognize the signature of a stutter as distinct from a real allele. Then when the post analysis ladder-check binning and labelling software cuts in why is the anomolous peak not labelled 'S' ,say, for stutter.

Concerning pulling data out of mush. Would you agree with me there are further minor peaks above the re-scaled (lowered) threshold that are in fact higher than the peaks arrowed in the 'mush-field' ? I can assure you those peaks are in the printed version and are not an artifice of a low resolution internet PDF file version. http://www.cmj.hr/2003/4403/18DROBNIC.pdf
Figure 1
The 3 lines of this B plot , including the arrowed sites are for 
D3, THO1, D21, D18, Penta E
D5, D13, D7, D16, CSF, Penta D
XY, vWA, D8, TPOX, FGA
The extra spikes greater than the 50 threshold that are not arrowed would be D21 (29) [ third set on top row ] D18 (14) ( Fourth set on top row ] and D5 (10) [ first set of middle row ] Neither suspect nor victim have these 3 alleles

Note the software could not be relied upon to output a reconfigured plot with lowered threshold level without labelling at least the 3 peaks D21(29) D18(14) and D5(10) hence, IMHO, the standard normal level threshold plot with non-standard added arrows. Not even fudging it by choosing some threshold level between 75 and 50 could things be manipulated to include the 'wanted' alleles and exclude the 'unwanted' alleles.

A fundamental tenet of science is the principle of reproducability. If I pick up a calculator and accurately enter a request for the tangent of 40 degrees and get the figure 0.839099631 assuming accurately transcribed. I expect you in another country to do the same on a completely different calculator and get the same figure with maybe a rounding diference on last digit.

In this CMJ report a sample from same source was put through 2 related processes and ended up with 2 different results concerning vWA. The interpretation that can be made with any authority is that vWA cannot be relied on and should not be a part of a system that incriminates. This 'science' is not reproducable so cannot be called a science.

I posit that there must be 10s of thousands of erroneous profiles in databses because of vWA stutter and 10s of thousands more because of false homozygosity recorded as real. Similarly but a third to half, the vWA erroneous profiles rate, for false homozygosity recorded as real in D8 , FGA and D18 and to a lesser extent D5 Data from FSI 143 (2004) 47-52

No doubt a 14 vWA allel can be real; however, you can not, I repeat, you CAN NOT determine the position of that peak or any other unlabeled peak from the data in that article.

The number of primer pairs is irrelevant with respect to stutter. If you believe the number of primer pairs has anything to do with stutter, then you clearly do not know what stutter is. Also I personally have not seen software that labels stutter. Further more, software does not interpret stutter, a trained analyst does.

Finally, no I do not agree there are minor peaks that are valid alleles after lowering the cutoff threshold. At least not with the information provided in the article. To make any true determination I would (and so would you) require the original data and appropriate software.

Have you actually ever done any DNA analysis? If so, what kit and instrument? I would never dare to make the claims you are making without seeing the data for myself. To do so (IMHO) would be irresponsible and wreckless. Every analyst I know takes the interpretation of STR data very seriously. We do not want to send innocent people to prison by forcing data to fit the story. This is a serious business we are in.

If it was all a proper science then there would be no need for 'interpretation' . The analysis should be automatic and unambiguous. Where there are anaomalies or ambiguities they should be picked up by dispassionate system filters and checks not post-analysis human 'interpretation' in your parlance and sleight-of-hand in my parlance. Bear in mind the whole process is in the first instance , and usually the last instance, commissioned at the behest of the prosecution.

Perhaps we are talking at cross-purposes.

On the second page , page 351, of article on http://www.cmj.hr/2003/4403/18DROBNIC.pdf Figure 1 B and on the bottom line , first group is the Amel one and the next group from the left is the vWA plot, as far as I know. Are you telling me you do not see a peak to the left of the 3 peaks labelled 15,16 and 17 ?

Agreed I cannot state with any conviction that this peak, I'll call vWA(*), represents an allele 14 or 13 or some variant as only a graphical plot. But there is definitely something there projecting well out of the mush-field, to my reading of it.

Without any prior knowledge ( ie victim and suspect only show alleles 15,16,17 ) and one pass using the PowerPlex system, how can the analyst declare this vWA(*) peak is an artifice of the system rather than real. In normal processing a validation repeat on the same sample, ie Powerplex here, is likely to show the same anomalous / real allele . Agreed, processing with another kit, SGM in this case, highlights this fourth vWA peak as questionable but my point is in normal, routine processing, what would indicate that this fourth peak was a stutter artifice. ? What signature (eg shape or position ) in the original electrophoretogram in isolation from any other information, would show , even if just presumptively rather than conclusively, that this vWA(*) was not real ?

I would conjecture that an SGM run was done because the vWA (*) did not fit victim or suspect, ie prior 'knowledge', that run failed to bring the minor contributions out of the mush-field, so nothing gained there.



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So you expect the data to analyze itself? Any science requires interpretation - how do you think new drugs are made? The researchers first have trials in which they plot data from experiments and then analyze or interpret what the data means for that drug's usefullness. Even a simple GC/MS of a drug needs to be interpreted to make sure everything is accounted for. Handing raw data to someone untrained and unfamiliar with the process would be the equivalent of handing me a soldering iron and expecting me to solder a microchip in place or handing my little brother a scalpel and expecting him to remove someone's appendix. Data must be analyzed/interpreted by a trained professional, just as a MD analyzes blood work and/or any test performed to find out what ails you.

One of the definitions of science is "knowledge gained by experience" (American Heritage Dictionary) or "knowledge obtained from the systematic study of the structure and behaviour of the physical world, especially by observing, measuring and experimenting, and the development of theories to describe the results of these activities" (Cambridge Dictionary). Instruments and/or computers do not gain knowledge by experience. They only do what they are programmed to do. Everything to a computer is reduced to 1s and 0s. A human programmer compiles a list of steps the computer must perform in its interpretation. So even if we allow the computer/instrument to perform the interpretation we are in fact still having a human perform the interpretation. However, the human involved is usually a computer science professional that does not necessarily have training in genetic analysis. Therefore, allowing the computer/instrument to perform the interpretation would possibly/probably cause greater errors than having a trained human analyst review the data and interpret the computers interpretation by rules set up during training and experience.



Thank you for so clearly expanding on what I said in my most recent (still not posted) reply to Nonarevers. His view of science is very idealistic and unrealistic. I almost used the GC/MS example in my reply:)

"If it was all a proper science then there would be no need for 'interpretation' ."

So you expect the data to analyze itself? Any science requires interpretation - how do you think new drugs are made? The researchers first

Automatic and unambiguous? First a lesson on software. Who writes software and filters? People do! So while it may (someday) be possible to write filters to fit every scenario, there is still the fact the filters are determined by human beings. As such, STR analysis is subject to interpretation since there will always be a human factor somewhere in the process. I disagree with the word ambiguous. It implies DNA analysis is uncertain or that there is always two ways to view the results. This is simply not true. When we encounter hard to interpret data then we always err on the side of being very conservative when stating an inclusion. Sometimes we can't make a determination and state as such.

As to your prosecution remark. Clearly it implies that all DNA analyst are just "cops in white lab coats" who merely manipulate the data to "make" the prosecutions case. While I can't argue there have been embarassing incidents within the community; a few bad apples do not reflect the attitude of the community as a whole. I know that within my lab we all would love to be independent of law enforcement just to remove even the appearance of favoritism. However, who writes my paycheck is completely independent of the work I do. Frankly I love to see a good case result in a conviction. I also am equally happy to see a suspect exonorated by my work. It all pays the same!

A final remark... I have to this day not seen any "proper science" that is automatic and unambiguous. The uncertain nature of things is why we have science. Automation... a luxury.



What is the major, unreported, flaw in this sort of statement seen in court houses around the world, reported in last day. http://www.thereporter.com/Stories/0,1413,295~30195~2543067,00.html <...> At that time, state Department of Justice criminalist Nicola Shea stated that Wilson's genetic profile would be expected to occur in 1 of 96 billion Caucasians, 1 of 180 billion Hispanics and 1 of 340 billion African-Americans. The victim's genetic profile, Shea said, would be expected to occur in 1 of 110 trillion Hispanics, 1 out of 140 trillion Caucasians and 1 out of 610 trillion African-Americans. Shea noted that the population of the world is estimated at 6.5 billion to 7 billion. <...>

I doubt no more than 100 million profiles have been determined in the whole world and no more than 20 million using one compatible profiling system.

Courts are for statements of fact not unfounded and untested speculation like the above quote. The correct statement should be of the form number of unrelated matches in the known 20 million profiles , or whatever number, and then from the rarity/commonness of allele frequencies concerning this defendent's alleles how likely he is to have a false match.

The UK government will not disclose how many unrelated matches there are in the 2.7 million arrestee side of the NDNAD and the FBI remove any from data before handing over to academe.

From doing multi-million profile simulations I know there are so many unrelated matches after 100 million population/ database that quoting billions let alone trillions ...... heptillions is tantamount to perjury.

DNA from cremated ashes ?

http://www.channelnewsasia.com/stories/afp_asiapacific/view/121429/1/. html <...>Tokyo announced Wednesday that DNA tests did not match ashes purported to belong to Megumi Yokota, who was kidnapped in 1977 when she was 13 by North Korean agents looking to teach spies about Japan.

Chief Cabinet Secretary Hiroyuki Hosoda said that another set of cremated remains brought from North Korea by a Japanese team last month were not those of another victim, Kaoru Matsuki, as claimed.

"We have told (Matsuki's) family members that the remains displayed someone else's DNA," the top Japanese government spokesman told a press conference. <...>

Which planet breeds forensic serologists ?

http://www.presstelegram.com/Stories/0,1413,204~21474~2300828,00.html Article Published: Wednesday, July 28, 2004 - 8:35:45 PM PST Quote When analyzing DNA, forensics experts tend to talk about numbers rarely heard outside college classrooms and science laboratories. They use terms like quintillions (a number with 18 zeros), sextillions (21 zeros) and septillions (24 zeros). And when it comes to matching DNA profiles, each zero matters. In the case of Mark Wayne Rathbun - the alleged Belmont Shore rapist - forensic serologist Thomas Fedor has calculated a chance of one in 844 septillion that someone other than Rathbun left his DNA on the left breast of victim Jane Doe No. 2 in May 1998.

But how did he get that number?

Such complex calculations, Fedor said, are based primarily on a population survey that indicates how many people in a group are likely to have the same information stored in their genetic markers.

For instance, Fedor said, if one in five people have the same information stored in one specific marker, then there's a 5,percent chance that two given people share that marker. If one in 10 people have another specific marker, then the percentage of people who share both these markers is calculated by taking 10 percent of 5 percent.

The calculation is simply repeated for each of the markers studied, Fedor said.

"If you take 10 percent of 10 percent of 10 percent of 10 percent 13 times, you're coming up with a very small number," he said. This formula, Fedor said, is called the Product Rule and is widely accepted in DNA analysis.



There's nothing wrong with the product rule, as it is a well established statistical principle. However, there are those who will tell you that it is too simplistic an approach to use in DNA analysis because genetic markers are not necessarily all independent variables. There are other more complicated statistical calculations which may apply and may or may not still produce astronomical results. Others will state that the question of "what is the chance of two people having the same marker?" isn't the appropriate question, but rather "what is the chance, given the frequency of this marker in the relevant population, that someone other than the suspect could have deposited the stain?" or rather "what is the chance that two people who share this marker could have been at the scene?" - The answers to these questions require a different approach, involving more advanced concepts such as calculation of "prior odds" and "posterior odds".

I'll let someone more qualified than me in this area (I'm just a drug chemist) explain the details of the above, but there is one glaring error in the below quote I can point out. A "1 in 5" chance is a 20% chance, not a "5% chance" as stated below, so the example calculation begins with a faulty figure. I would wager that Thomas Fedor was misquoted in this regard, as I'm sure he can do primary-school level mathematics, but I'm less sanguine about the abilities of journalists who write articles like this one. One should never trust the average journalist with math, let alone with science - they often mangle both into unrecognizable forms. If you seek accurate information in the mass media (itself not a particularly reliable source) regarding science, try to read pieces written by journalists who specialize in science news and who themselves have a background in science, such that they actually have some understanding of their subject matter. Most of the rest know nothing of which they speak, and almost invariably get it wrong (or at least not entirely right) when reporting about it.

No, - statistics are valid for extrapolating from billions or trillions dowwn to say a country's population. Not the other way around let alone a small subset of a country. Please tell me where all these billions or trillions of profiles have been determined.

I've still not found anyone else in any discipline who has taken realworld allele frequencies and simulated multi-million DNA profile database detailed fully on http://www.nutteing2.50megs.com/dnas5.htm If , like me, a defendent should have in all (UK NDNAD terms) 20 alleles, characterised by allele frequencies greater than 8 per cent then talk of billions or trillions before an unrelated match is found is totally unproven and as such should not be stated in courts. Another disturbing aspect appeared this week http://www.harktheherald.com/modules.php? op=modload&name=News&file=article&sid=43190&mode=thread&order=0&thold= 0 or http://tinyurl.com/4r2r5 This prisoner has no matching MO and no other evidence just a profile match which IMHO is entirely inadequte when databases are containing millions of profiles now.

I still have not found out which planet has billions, trillions, quadrillions .... heptillions of humanoids to take profiles of to be able to scientifically and legally make such statements in an earth-based court. Once you get to a database of a few hunreds of millions in the Australian NIFS system, a million or so in the UK NDNAD system or 10 or so millions in the CODIS database then you have unrelated false matches appearing. Remember CODIS, for false match purposes, is effectively only 12 loci, not 13 because 79 percent of people have at least one TPOX (8) allele. All you can state properly in court is there is not a match to this defendent in this database of ? number profiles. There are ?? unrelated matches within this database. Then it is a matter of stating how the individual alleles in this defendant's profile compare with the allele frequencies of occurance in his genetic/ racial supopulation. Quoting totally unsubstantiated multi-billion numbers are just there to colour the perceptions of the jury - they have no scientific validation. The hundreds of papers by forensic statisticians are a blot on an otherwise admirable molecular biological science. They have woven Scotch mist to make something admissible in court.



It seemed a very strange comment "I have a healthy disrespect for statistics" from a person who is using statistics to the extent of conducting statistical simulations in attempting to prove a point!!

Chris Anderson

It is very easy to understand this stance on statistics. If you (or one of your close family members) was accused/arrested/convicted of a crime, you also might try to start some movement to falsely discredit the science that caused the accusation/arrest/conviction. It is very easy to avoid the science and math and create your own world where the truth doesn't make sense. Fortunately, people like "nonarevers" will never be on a jury here in America, for at least two reasons:

1) He is totally biased towards his own brand of nonsensical pseudoscience 2) He isn't an american

I'm not really sure who he is attempting to persuade with his crusade of idiocy, but it is probably best for all of us if we just ignore his rants.

I'm not understanding this stance on statistics. Here in KY our database seldom generates hits because the markers we use are highly variable and highly individual. We use 13 STRs. I've seen the research and read the papers. I've seen the research and statistics applied to horses, dogs, cows, cats and mice. It makes sense. The article given may not make sense, but then again how many mainstream media types can actually get something like that right? DNA has been through the hearings and been approved. Its not perfect, nothing is, but its a definitely better than IEF blood typing for generating more unique results. At least that's my opinion and that of my coworkers.

Well Adam, his (or her) posts seem very emotional to me. I would guess that "nonarevers" has suffered personal harm because of what he/she perceives as undue reliance on DNA evidence in a particular case. Perhaps a lover or a relative convicted by it. I have had a few testy exchanges with him/her. But I actually think that the "statistics" are so overwhelming, at this point, that a positive result is simply a match, and the numbers don't count for very much. "one in the world's population" pretty much says it all. There will be times when there are false results due to poor procedure or wrongdoing but, in the normal course of things, its as routine and boring as a blood alcohol or drug analysis.

A true forensic scientist would only pontificate after experimenting to confirm or counter some hypothesis. Where is your evidence that you will only find false matches when databases get to off-the-planet 'populations' of trillions ..... heptillions ? I have the authority of being able to speak as someone who has simulated multi-million profile numbers based on real-world data not some hypothetical head-in-the-clouds theoretical statistics.



Nonarevers, Circular logic will not get those people released from prison. DNA is a scientifically well founded way of showing that two samples share a common source. The stats are so overwhelmingly supportive of the techniques used that even if your thesis about false matches were reasonable, the odds against more than one of these false positives would be astronomical. The argument has been had and won by the science. Defense lawyers lost this one. The FBI just calls it a match, as I understand it. Concentrate on the integrity of the laboratory procedure, as a procedure, and on scene contamination. That is a much more likely source of reasonable doubt. Your not doing these people any favors by pinning their hopes on air, or on some esoteric philosophy of science argument. You have a better chance of convincing juries that martians did it, a much better chance, they believe in martians.

No one is lying or exaggerating. There is no vast conspiracy to falsely imprison your friends. There are mistakes made, even wrongdoing on the part of a very few forensic workers. That does not change the fact that DNA profiling does what it claims to do. We believe it because we have no choise, its scientifically and legally valid. I'm not trying to shut you up, I'm really not, but I dispute the practical validity of you arguments. Happy New Year!



Nonarevers.

I would like you to do a simple favor for me. Take 26 equally weighted dice. Throw them together and see if all of them land with 3 on their top face. It should only take you a few seconds. Now grab another 26 dice and do the same. Keep repeatinig with sets of 26 dice until you have all 3's up. It will brobably only take you a couple of trillion years or so. Oh, you won't live that long? You don't have 3.4 quintillion dice? There aren't even a 3.4 quintillion dice in the whole world? Then I guess statistics and probability theory must not be valid on our planet. Just because something has a large (or small) number doesn't mean that the theory behind it is invalid.

When you take many independent observations (whether they are tosses of dice or combinations of independantly inherited genes) and try to figure out the probability of finding any specific combination of those events, the numbers can be very large if the number of observations are large.

I've given you a free pass for most of the year, but your drivel has finally irked me to a response. I am now satiated and will allow you to pollute the web with misinformation until you instigate a response.

I find it amazing that you don't even appreciate the fundamentals. Your dice are proper balanced dice but real life uses loaded dice.

Just taking as an example a THO1 'UK Caucasian' dice of '8 sides' they are not equal probability of 0.125 of each face turning uppermost
For THO1 
'Face5 ' probability 0.002
Face6 ,  0.241
Face7 , 0.194
Face8 , 0.108
Face8.3 , 0.001
Face9 , 0.14
Face9.3 , 0.304
Face 10 , 0.012

So faces 9.3 and 6 are far more likely to appear than 1/8 at each toss. Repeat this twice and for each of the other loci and there are always more commonly occuring alleles. For people like myself with no criminal record but my DNA profile permanently on record and allele frequencies at all loci greater than 8 per cent then I am far more in the firing line to be falsely arrested in the future just because my profile matches a crime-scene profile.

I have done this 'dice tossing' with all loci/alleles represented and the results do not tally with your assumptions.

At least I have simulated on computer all these dice, modelled on real-life allele frequency data (loaded dice). For 6 loci , 12 datapoints, then unrelated matches start apearing at about 10,000 throws. Remember court experts ,were stating at that time, pre-2000 false match probabilies of 1 in 37 million. For 9 loci ,matches start appearing about 200,000 For 10 loci about 1 million For 13 loci about 10 million

Which planet breeds forensic serologists ?



Here is a ragbag collection of statements in various courts. I thought, niaively, that courts were for presenting facts and proveable/ testable evidence.

"The odds against another individual matching Danielle's profile are in the quadrillions, said Mitchell M. Holland "

"Chidambaram said. ``With this new method, the chance is one in quintillions So the chance of identifying a particular person is pretty high""

"... occurring in approximately 1 in 21 sextillion of the Caucasian population, 1 in 650 quadrillion of the African American population, 1 in 420 sextillion of the Hispanic population."

"Thomas Fedor has calculated a chance of one in 844 septillion that someone other than Rathbun left his DNA... "

Well Adam, his (or her) posts seem very emotional to me. I would guess that "nonarevers" has suffered personal harm because of what he/she perceives as undue reliance on DNA evidence in a particular case. Perhaps a lover or a relative convicted by it. I have had a few testy exchanges with him/her. But I actually think that the "statistics" are so overwhelming, at this point, that a positive result is simply a match, and the numbers don't count for very much. "one in the world's population" pretty much says it all. There will be times when there are false results due to poor procedure or wrongdoing but, in the normal course of things, its as routine and boring as a blood alcohol or drug analysis.



Wally Lind relates, "Concentrate on the integrity of the laboratory procedure, as a procedure, and on scene contamination."

Oh Wally, he has. A quick read of his website shows that Paul (nonarevers) has a suggestion for the potential rapists out there...

"For rapists all you have to do is pick up recently discarded condoms from prostitute working areas. Place in your freezer and leave the unfrozen contents of one smeared on your next victim - use a condom yourself of course. Forensic scientists do not routinely check for previous freezing of such samples. They often place such SoCo exhibits in a freezer anyway."

http://www.nutteing2.50megs.com/dnapr.htm

I stopped responding to his posts a long time ago and treat all messages posted by him as spam.

Just my two-cents.



Perhaps I should of acknowledged assistance on the background technical matter by reference to message 6367 on 05 March ,2004 of this group "The thing is that crime scene semen is typically collected, dried, then sent to the crime lab, and then processed for typing. This is usually weeks after collection and the lab might even freeze it to preserve the stains, especially if case work it backlogged. And, In these days of DNA testing, where serological testing is almost never done, I doubt if the physical signs of freezing would be notice d at the lab, in most circumstances. "

INTERNET CRACKPOT HOGWASH, straight from the anti-establishment lunatic fringe. A guy who gives forensic advice to rapists on his website, is in need of a few "fundamentals" himself. Like maybe some common decency.

I thought this subject was beaten to death in Summer/Fall of 2003. Message #5174 put a stop to him for a while but I suppose he's found renewed energy as of late...

nonarevers,

So in other words you don't believe in extrapolating statistics? I don't claim to be a statistician, but from my limited statistics experience what DNA analysts say is scientifically valid. Forensic scientists are generally very cautious when saying something matches. It seems to me that you are taking only one side without throughly knowing the science of both sides. As far as I know, there are no other planets with humanoids - much less trillions or quadrillions. However, science here on Earth has led scientists, statisticians, and forensic analysts to believe that the probability of someone having the same DNA profile is very large. Have you looked into any of the databases to see how many, if any profiles are the same? Have you examined numerous pieces of evidence and done the procedures necessary? Do you know your human genetics and how random assortment and crossing over and other genetic phenomenon occur? Or are you going on an oppositional rampage insisting that because you don't understand and/or you don't want to understand that the science is unfair and untrue? I've looked at the link you gave, and all I found was someone's idea of the truth that they spout with some knowledge, but not understanding. I'm very hesitant to accept things just because someone says its true - especially when that someone is going against all other proof. The person responsible for that website you keep linking to is more than a little off-base. He/she indicates in this area

"The second line of text on the above covering letter ending "the record mas made". THIS IS A DYSLEXIC ERROR - letter reversal/inversion - not a typing error, w and m are nowhere near on a keyboard (also occurs in dyslexics concerning letters u and n, d and b etc). The other indicator for dyslexia is this erroneous initial letter is the same as the initial letter of the next word. Typing letter q, e, a, s or d instead of w is just sloppy fingers on the keyboard a letter m indicates a sloppy mind. If this person is involved with the likes of labelling DNA samples or batches then god help us. "for the for the" shows lack of proof-reading / lack of managerial supervision. What do defence attourneys make of such evidence of incompetence when it arrives on their desks from this country's supposed leading national forensic laboratory."

Not only is defamatory to any number of dyslexics out there (of which I am one), it is also highly prejudiced. Also, while the writer goes on about 'sloppy minds' and 'sloppy fingers' they do not puncuate correctly nor do they spell correctly (defence to my knowledge is not a word - defense is the proper spelling). To call a dyslexic a 'sloppy mind' is like calling someone blind ignorant. Also, even if the person inputting the data is dyslexic and turns a word around or inputs an improper character, peer review will catch errors. That is why at least in my state every profile entered into the system has at least 3 analysts review it - first the initial analyst reviews their data, they then submit it to another qualified DNA analyst for review. This analyst reviews not only the procedures followed and statements made, they also check the spelling (for lack of a better term) of the alleles. After that analyst is finished reviewing the data, a DNA database analyst reviews the work all over again, making certain that the information printed out by the instrument is what appears in the analysts report. Often, another analyst will review the data at a later time during an audit or similar process. We are human, so errors may be made, but it would be statistically unlikely that 3+ people would all make the same mistakes. I am proud to be trained in molecular biology as well as trained in forensic serology. I admit that erros do occur, but the entire group cannot be judged on the basis of so few. It would be like saying, since we know some people steal/cheat/kill/etc the entire human population is untrustworthy and wrong at all times. Quoting only small sections of a literature reference is like quoting only a word out of a sentence. I don't know what has happened to you in the past to make you see things so jaded, but I hope for you the best.



Dyslexia is a potential problem in many areas of work eg delivery driver, postman etc. But it pales into insignificance compared to being employed in forensic science even only as a clerical officer producing reports. A mistake by a dyslexic in such an environment could lead to the death of an innocent in many USA states. Leaking roof over forensic lab sample-preparation area (Texas) is considered OK by one set of lab directors so perhaps dyslexia is perfectly acceptable also. Not in my books though. I've only been in receipt of one communication (ignoring repeat copy due to administrative incompetence ) from the supposed premier UK forensic lab in Birmingham, England. This letter was mimeograph signed by the then director a Dr P E Cage. In it was prima facie evidence of dyslexia and lack of proof reading by whoever scripted the letter and also evidence of technical incompetence concerning confusion over D6/D8 loci. The then director put his name and signature to this document so condoning the lack of ability of his staff by lacking the ability to spot the errors, himself, or equally wrongly by not reading what he puts his signature to.

Comments about spelling or use of English should be on the appropriate board/group.

To exonerate someone I would expect on average at least 5 'alien' peaks in an electrophoretogram that are not present in the incarcaree or victim + incarceree, mixed crime-scene stain. One mismatch can be (suspiciously too often ) explained away as spontaneous mutation but 5 or so ? Unless you are somehow saying that a historic criminal deliberately seeded a crime-scene with someone else's DNA on the off-chance that a future technology would exonerate him.

In theory it takes (USA) 26 in 26 numbers to, truely or falsely, implicate a person but only one in 26 to exonerate.

I wonder if any forensic lab technicians have been falsely dismissed because it is easier to dismiss one lowly employee rather than overhaul an ingrained country-wide system. People dismissed because it is implied they cross-contaminated samples whereas in my 'theory' the results could well be correct. But as it is deemed impossible for false matches then blame the worker and not the system which can bungle along untrammelled producing yet more miscarriages of justice. What the hell, the vast majority being implicated via DNA databases are criminals anyway. My details are in such a database, not because I have a criminal record or conviction , but because of the activities of corrupt social workers and then a Stalinist regime in political power in the UK.



Followup to previous concerning the Minimum Allele Frequency Formula before matches appear. Scaling the AF tables for the high AF situation and then using the minimum number for matches formula produced the following.

Calculated minimum numbers for sub-sets of profiles like 
mine of > 8 per cent AFs , also for >3 per cent ,Codis case.
6 loci UK Caucasian for >8% then 2,400
10 loci UK Caucasian for >8% then 280,000
9 loci Australian Caucasian for >8% then 44,000
9 loci Australian Aborigine for >8% then 21,400
13 loci USA Caucasian for >8% then 2 million 
13 loci USA Caucasian for >3% then 10.2 million

If anyone here would like to compare their own DNA profile through the published AF tables for the relevent principal population subgroup and reveal what their minimum AF (FST/theta - like) is I would be interested. My minimum is 8.7 per cent, for UK Caucasian , all the remaining 19 are higher than 8.7.



Michael,

Bravo - even I the nonstatistician understood your logic. Of course, that implies that for someone to understand they must at least acknowledge logic... I'm not sure Paul goes that far. Very good presentation of his thesis only more thought out and logical... without the 'fundamentalist' mentality.



I would dearly love to interrogate the likes of the FSS NDNAD . The last time anyone published any figures of matches within this database was around 1997 ie 6 loci days.

From journal Forensic Science International 95 (1998) p30.

Concerning data in the UK DNA database as of 04 October 1996 when there were only 6311 samples from the London area and 573 from the Cardiff area. "A small number of unresolved duplicate pairs of profiles were present in the regional data :10 pairs within the London region and 1 pair in Cardiff. " Apparently not investigated further, for aliases etc or at least reported. About the same time there was a TV report of about 600 matches (transcript/provenance of this not available other than details of the program scheduling ) for the whole NDNAD in mid 1990s.

Despite repeated written parliamentary questions the Home Office/ FSS will not divulge the numbers of 10 loci matches. Until they do I rely on my simulations. Standard conventional statistics does not explain the numerous occurances of false matches, and I'm not refering to contamination events.

It was not just dyslexic errors. In the printout of my profile D8S1179 on the 8th chromosome is referred to as D6S502 on the 6th chromosome. To me showing gross technical incompetence. An exact copy of this recorded delivery letter was sent recorded again a few days later. Strongly suggesting managerial incompetence. All I can say it is fortunate that the UK no longer has the death sentence.

I am a scientist , not prose writer. Full of poor grammar etc, I'm sure, but I will only correct the English if it leads to ambiguity.

As far as multiplying your figures together I end up with the same order of result.

BUT

Firstly DNA profiles consist of directed number pairs and 2pq is usually greater than p^2 where p is the largest and q the next largest (q usually < 2p) . Intuitively I thought excess homozygosity would lead to greater false match likelihood - not true. This is yet another myth that seems to be prevalent.

Secondly I don't have the computer power to simulate 10s of millions of CODIS profiles. I can really only vouch for 10 loci, multi-million 'profiles' simulation. In all the runs I have done then any 10 loci matches have occured where the minimum allele frequency in those profiles is >= 5 per cent. Again for the UK, in the low millions on the NDNAD, it is people like me >8% AF that are in the firing line. I suspect when the numbers get to 10 million odd then >3 %ers start getting snagged. Incredibly there seems to be no awareness within the forensic community of this phenomenon. I would have thought it would have been an automatic adjunct where a suspect is found by database match Just flashing up the minimum AF of this person relative to their ethnicity to avoid the Raymond Eastopn / Peter Hamkin false arrests let alone the others that have gone on to prosecution.

Conventional statistics is not showing up these "all-high allele frequency matches". People with a single <1% AF occurance in their profile are likely to be fairly immune from false matches. It requires someone with greater computer power and background research data to simulate for unknown half-brothers and cross-linking of loci/alleles where these persons may start to be implicated. I have been very rigorous checking that any matches are not a manifest of the pseudo random number generator and they are not.

I do not consider myself to be exceptional as far as genetic ancestry. One parent and his parents from one county and other parent and her parents from another county. Coincidence that my minimum AF is 8% ? - I don't know. There just is not anything in the public domain correlating minimum allele frequencies to ancestral/ichthonous backgrounds. For all I know all 6 forebears from the same county may mean a high probability of such people having min AF of >=10%.

I would like to be able to point to other researchers who have explored such avenues but I seem to be on my own. I have a healthy disrespect for statistics.

I've gone back 5 years, in effect, and compared the standard statistical analysis with my simulation method but for just 6 loci as the computer processing is easily handlable by anyone. It puts it all into stark contrast.

UK 6 loci AFs for Caucasians (allele in brackets)
Locus /	p / 		q /  		  2pq
vWA	0.27 (17)		0.219 (18)		0.118
THO1	0.304 (9.3	)	0.241 (6)		0.147
D8	0.333 (13)		0.209 (14)		0.139
FGA	0.187 (21)		0.165 (22)		0.062
D21	0.258 (30)		0.226 (29)		0.117
D18	0.164 (14)		0.145 (15)		0.048

Product/reciprocal gives near enough 1.2 million

Then using my random simulation generation Visual Basic code for full 10 loci, employing all IJLM published alleles. Doing a cut-down run of 45,000 'profiles' then finding matches on the first 6 loci and ignoring the last 4 loci gave these 12 pairs of matches.

Actual results of a run on 07 Jan 2005 vWA,THO1,D8,FGA,D21,D18 (17,17)(6,7)(13,13)(21,22)(28,30)(14,15) (17,17)(6,7)(13,13)(22,22)(28,31.2)(12,13) (17,17)(7,8)(13,13)(23,23)(29,32.2)(15,16) (17,18)(6,9)(13,14)(20,23)(29,30)(18,18) (17,18)(7,9.3)(13,14)(21,23)(30,31)(12,12) (17,19)(9,9.3)(13,15)(21,25)(29,30)(14,17) (16,16)(7,9.3)(9,13)(23,23)(29,30)(14,18) (16,17)(6,9.3)(13,14)(22,23)(28,30)(14,15) (16,19)(7,8)(13,13)(18,20)(30,32)(13,14) (16,19)(7,9)(10,12)(22,24)(30,31)(16,18) (14,16)(6,8)(13,13)(19,20)(28,29)(14,16) (14,17)(7,9.3)(12,14)(22,24)(30,31)(12,14)

The minimum AF in the above is for D8(9) of 0.013.

There is no correlation between 1.2 million and 12 in 45,000. There is no point in discussing 10 or 13 loci before fathoming this glaring anomaly.

The VB code and macros are detailed below. This is just plain text , so anyone can see there is nothing like virus code - it is compiled at Run-time. For longer runs I have automated the procedures a lot but a 45,000 run is short enough not to require more than single sorts per sub-file.

Requirements: a copy of Word 97 with Visual Basic and Macro handling (in Tools section ). I only have an 8 year old PC and don't know if the code works unamended on later versions. Copy the generator routine beween Sub and End Sub in the Run/ Create section of Word / VB. Set to 45,000 (actually 44999 ) and find/replace all dec14 file names to jan08 (or whatever) and Run - takes about 1 minute on my pc. Gives 8 non-empty string subfiles, convert back to standard representation at the end. Sort each one in turn using Word text sort - takes about 5 minutes in total. Copy and paste back into one file - about 4 minutes in total. Copy the "find matching pairs " routine to VB and change to 45000 and file name and run - about 2 seconds. My run produced 12 '6 loci' matches , changing to 13 gave 2 off (6 loci +1) matches, 14 and no 7 loci matches. Because a random process anyone repeating this process instead of 12 matches you may end up with only 5 or maybe 20 or anything but something of order 10. To give standard representation use the final conversion routine , set to ? (12 in my case) and correct file names then in output file find/replace ,"", to )( to tidy up and delete the final 4 pairs in each profile.

This is base-line totally random matching, no factoring in of co-ancestry, cross-linking etc.



That's interesting since I went to your website and observed that YOU found no 20 digit (10 STR marker) matches in a run of 795,224 profiles using your macro; found one 10 marker match in 546,224 profiles; another one in 10 marker match in 1,220,712 profiles; and yet another one in 10 marker match in 999635 profiles.

That's a total of 3 matches in over 3.5 million profiles for all 10 STR markers using your simulation.

You failed to run more than 10 loci, so I would be cautious about drawing conclusions about 13 loci since your own data doesn't support this supposition.

It also appears to me that you have a biased method of limiting the number of alleles to (generally) ten. For example, you ignore all of the larger FGA alleles. Granted, these are rare, but your simulation doesn't reflect authentic, real world observations (e.g. there have been 51 observed alleles at D18, you used 16 alleles in your simulation).

I courteously acknowledge that you looked into it. I can only use the published data. I had initially only used a maximum of 10 alleles (0 to 9 in the strings) and was advised to add the minor ones and revised the structure to cope (0 to 9 and a to z ) but it made no observable difference as far as matches were concerned. False matches in 10 loci only occured in the 18 I've observed at AF > 5 percent. For 6 loci > 1 per cent.

These are the 18 'profile' matches found in numerous multi-million runs,
vWa,THO1,D8,FGA,D21,D18,D2,D16,D19,D3
(15,18)(6,7)(12,13)(23,25)(28,29)(14,16)(17,23)(11,12)(14,14)(14,17)
(16,17)(6,9)(13,15)(21,23)(29,30)(14,15)(17,20)(11,12)(13,14)(17,17)
(16,18)(7,9.3)(12,13)(21,22)(29,31.2)(12,15)(19,20)(11,12)(13,15)(14,18)
(17,18)(6,9.3)(11,13)(19,20)(29,30)(12,18)(19,23)(11,12)(14,14)(15,17)
(17,18)(6,9.3)(12,13)(20,21)(28,30)(12,15)(17,23)(11,13)(14,14)(17,18)
(17,18)(7,9.3)(12,16)(22,24)(28,30)(12,16)(18,25)(12,13)(13,14)(15,15)
(17,18)(8,9)(13,14)(21,22)(30,31.2)(14,16)(17,25)(11,12)(13,14)(15,16)
(17,18)(8,9.3)(13,13)(20,21)(29,30)(12,14)(20,24)(12,13)(13,14)(15,16)
(15,16) (6,9.3) (13,13) (20,23) (29,30) (15,17) (20,25) (9,11) (14,15) (14,16)
(16,17) (7,8) (13,15) (20,24) (29,30) (13,17) (21,24) (12,12) (14,15) (17,17)
(16,17) (9.3,9.3) (13,14) (20,22) (30,30) (12,14) (17,23) (12,13) (13,14) (16,17)
(17,17) (7,9.3) (12,13) (20,23) (28,30) (15,16) (18,24) (12,12) (13,14) (14,14)
(17,18) (6,9.3) (10,13) (18,22) (28,31) (12,18) (17,20) (12,12) (13,14) (17,18)
(17,18) (6,9.3) (13,14) (20,23) (28,29) (13,14) (17,20) (11,12) (14,14) (15,17)
(17,18) (6,9.3) (14,15) (21,24) (29,30) (14,14) (17,24) (11,12) (13,14) (15,16)
(17,18) (8,9) (13,14) (20,22) (30,30) (14,15) (20,20) (12,13) (13,14) (16,18)
(17,18) (8,9.3) (13,14) (20,23) (28,30) (15,17) (17,24) (11,12) (13,14) (15,16)
(18,18) (6,9.3) (12,14) (20,21) (29,30) (13,14) (20,25) (11,13) (13,14) (15,17)

I have done one 10 million 13 loci run and no match found but I don't have the computer power to go beyond that.

But the immediate problem is how to correlate a figure of 1.2 million by one method with 12 in 45,000 in the more basic 6 loci case. 12 in 45,000 is more in agreement with published matches eg the Janet Chaseling (Australia) one 7 loci (14 point ) match in 9 loci from a study of 5,500 unrelated people. That is any 7 from 9 , not the first 7 ,say. And the other reported matches in the 6 loci NDNAD when the total was less than 840,000.

Statistics versus Simulation.

To-a-man forensic scientists seem to use the product rule for determining what the likelihood is of finding a matching DNA profile to a given defendent. The Product Rule: - Mathematical rule that the frequency of occurrence of several independent events is equal to the product of their individual frequencies.

I have done exact simulations of large DNA profile databases and the figures in no way tally. Would anyone care to ponder?

Glossary Locus a recognisable site on a specific chromosomal DNA that has a repeated code sequence of bases A,G,C or T . Alllele is the number of repeats of this code at that locus Allele frequency (AF) is the fraction of a population having that particular allele at that locus, determined from sampling real people.. So in table below the maximum 'p' is 27 per cent for locus vWA and allele 17. The next most frequent 'q' is 21.9 percent. 2pq because there are 2 alleles at each locus because one is from mother and one from father. Which, from which, is usually not known and so expressed as directed pairs (smaller,larger) by convention.

UK 6 loci AFs for Caucasians (allele in brackets)
Locus / p /   q /      2pq
vWA 0.27 (17)  0.219 (18)  0.118
THO1 0.304 (9.3 ) 0.241 (6)  0.147
D8 0.333 (13)  0.209 (14)  0.139
FGA 0.187 (21)  0.165 (22)  0.062
D21 0.258 (30)  0.226 (29)  0.117
D18 0.164 (14)  0.145 (15)  0.048

Product/reciprocal of 2 pq column gives near enough 1.2 million for most commonly occuring pairs, ie worst case situation. Forensic scientists expect the first random matches to start occuring with a population or database greater than 1.2 million. For 10 loci they state billions and for USA , 13 loci, then trillions.

Random simulation generation Visual Basic code for full 10 loci, employing all IJLM published allele frequencies , URL below. I had to throw out 2 pseudo-random generators which weren't up to the task. Doing a cut-down run of 45,000 'profiles' then finding matches on the first 6 loci ( ignoring the last 4 loci as set for 10 loci ) gave these 12 pairs of matches, ie 24 'profiles'.

Actual results of a run on 07 Jan 2005
for 6 loci vWA,THO1,D8,FGA,D21,D18
(17,17)(6,7)(13,13)(21,22)(28,30)(14,15)
(17,17)(6,7)(13,13)(22,22)(28,31.2)(12,13)
(17,17)(7,8)(13,13)(23,23)(29,32.2)(15,16)
(17,18)(6,9)(13,14)(20,23)(29,30)(18,18)
(17,18)(7,9.3)(13,14)(21,23)(30,31)(12,12)
(17,19)(9,9.3)(13,15)(21,25)(29,30)(14,17)
(16,16)(7,9.3)(9,13)(23,23)(29,30)(14,18)
(16,17)(6,9.3)(13,14)(22,23)(28,30)(14,15)
(16,19)(7,8)(13,13)(18,20)(30,32)(13,14)
(16,19)(7,9)(10,12)(22,24)(30,31)(16,18)
(14,16)(6,8)(13,13)(19,20)(28,29)(14,16)
(14,17)(7,9.3)(12,14)(22,24)(30,31)(12,14)
(ignoring the last 4 pairs in each generated profile) No way involving just the most frequently occuring pairs of alleles.

There is no correlation between 1.2 million and 12 in 45,000. 12 in 45,000 seems closer to the reported situation . A 7 locus match in 5,500 unrelated Australian people and 300 6 loci pair matches in the UK forensic DNA database when the number of samples was about 200,000.

The problem would seem to be related to the "birthday problem" ie number of people for 2 people in the group to share the same birthday and the number for 2 to share the same specified birthday.

The reported matches in the vicinity of 6 loci are 'Janet Chaseling' 7 loci match in 5,500

Forensic Science International 95 (1998) p30 - all 6 loci 10 pairs within 6311 of the London region, arrested and sampled and 1 pair in 573 samples from Cardiff region, arrested and sampled

And the TV reported 300 pairs , 6 loci, when the NDNAD had about 200,000 arrestee profiles in about 1996/7.

I spent about an hour doing a 200,000 run using the semi-automated procedure (URL below) "split sorting" hands-on the '0' ,'34', '35' and '45' subfiles, the remainder 10 to 79 sorted by macro. This generated 291 matches on 6 loci 43 on 6 loci plus first of next pair 7 pairs of 7 loci matches.

There is a square law for all this " Double the population and you quadruple the number of matched pairs approximately". Some co-workers derrived this law - it's a first order simplification because triples, quadruples matches etc soon start confusing the situation. Previous simulation - 12 pairs in 45,000 I could predict when scaling from 45,000 to 200,000 (200,000/45,000)^2 x12 or 237 This square law effect means that once you start getting matches , whether 6,9,10 or 13 then it becomes a rapidly accelerating situation above that. For example in an otherwise 10 loci database soon after the fist paired matches appear then triple matches on 18 or even 19 datapoints rapidly become manifest.

The simulations as used here are totally random with nothing factored in to represent shared genetic history which of course increases the number of matches. It is as though they were all parthenogenic , spontaneously born, with no mother or father. Just the allele frequencies of all 45,000 or 200,000 are in agreement with the reported background population AFs. Match numbers in "ball-park" agreement with the reported situation and nothing like 1 in 1.2 million chance of a 6 loci pair match.

Neither UK nor USA have published how many higher number loci matches are within their databases. The FBI removes any before passing to academe and the FSS keep a tight hold.

It is as though you are setting up a lottery draw with balls of different sizes and masses and expecting the results to agrree with the normal balanced ball situation.

Reductio ad absurdum. Decided to do a 15,000 run - the maximum number that can be sorted in one go by my copy of Word97.

Resulted in 2 pairs of matches on 6 loci , ignore the 7 to 10 loci. As this is a random process the next run may be only 1 or maybe 3 or even 0 matches, although unlikely 0.

"15565624263618261335"
"44165536135723451746"

Started as undirected pairs "441655361357A1435345" "44615563317523457146" and "51566542266318261335" "51565642623611057545"

Converts to standard form vWa,THO1,D8,FGA,D21,D18,D2,D16,D19,D3 (14,18)(9,9.3)(13,14)(20,22)(29,31.2)(14,17)(17,24)(10,14)(13,14)(15,17) (17,17)(6,9.3)(13,13)(21,24)(28,30)(16,18)(18,19)(12,13)(13,16)(16,18) Again ignore loci 7 to 10

URL below . For this seriously cut-down case reduce the 10 subfile statements at the end of the generator routine to just one and no If / End If. Change filenames to suit and change run number to 15000

2 pairs in 15,000; 12 pairs in 45,000; 291 pairs in 200,000. Where is your justification for 1 pair in 1.2 million for 6 loci false matches ? Again no co-ancestry (high minimum allele frequencies ) or cross-linking factored in, all plain parthenogenic.

Another USA false DNA profile match

A very simple explanation although extremely awkward so not mentioned in this newspaper report. DNA profiles (twins apart) are not unique.

DNA findings questioned in 1969 slaying http://www.mlive.com/news/kzgazette/index.ssf?/base/news-12/1105788089296710.xml Part Quote Saturday, January 15, 2005

ANN ARBOR -- Gary Leiterman's DNA was identified on five locations of the pantyhose Jane Mixer was wearing when her body was found in 1969, a Michigan State Police crime lab analyst said Friday.

The chances of someone else having the same DNA profile is more than 100 trillion to one, the analyst said at the Gobles man's preliminary examination.

A drop of blood found on the back of her hand, however, was earlier identified by the same analyst as belonging to a convicted murderer who was only 4 years old when Mixer was killed. <...>

Someone else who is getting his come-upppance for mis-applying the product rule - Prof Sir Roy Meadow. He of Meadow's law, One cot death is unfortunate, two is suspicious and three is murder. He manafged to correlate probabilities of 2 in 3 and 1 in 1 with 73 million to one. see http://www.mth.kcl.ac.uk/~streater/cotdeaths.html



Bull, The Analyst screwed up the procedure. That is the simple explanation, and the true one.

A very simple explanation although extremely awkward so not mentioned in this newspaper report. DNA profiles, even USA ones, (twins apart) are not unique.

DNA findings questioned in 1969 slaying http://www.mlive.com/news/kzgazette/index.ssf?/base/news- 12/1105788089296710.xml Part Quote Saturday, January 15, 2005

ANN ARBOR -- Gary Leiterman's DNA was identified on five locations of the pantyhose Jane Mixer was wearing when her body was found in 1969, a Michigan State Police crime lab analyst said Friday.

The chances of someone else having the same DNA profile is more than 100 trillion to one, the analyst said at the Gobles man's preliminary examination.

A drop of blood found on the back of her hand, however, was earlier identified by the same analyst as belonging to a convicted murderer who was only 4 years old when Mixer was killed. <...>

I come from a scientific background where if theory does not fit the facts then you have to revise the theory - not ignore the problem and hope it disappears. Just because the likes of Weir, Evett, Balding and Gill use the product law and hundreds of publications mention it - it is unproven. Repeating unproven material , however often repeated, does not make it true.



Since DNA typing was invented in 1984 in England, 16 years AFTER "nonarevers" case, there is something very very fishy about his post, don't you think?

The DNA profiling was done in 2002 on evidence preserved (presumably in police custody) since 1969. The crux of the controversy appears to be that one of two men identified in a mixed sample taken from the victim's clothing would have been only 4 years old at the time of the crime. Hello all- I have been reading posts for a short while now and can't help to feel disgust with this topic that keeps appearing from "nonarevers". This case he is refering to happened in 1969! Do you not think that as time has advanced, so has technology? Not only that, but for goodness sake, people make mistakes. I am not saying it is excusable but since you keep bringing up USAs errors, has your country made any mistaken DNA IDs? Im sure they are far more advanced than those scientists here. [hidden sarcasm] Do you not have anything better to do?

That would seem to be a problem, even if it was pointed out by our listmate.



What a strange turn around - you blaming one of your colleagues and me blaming the system where the background mathematics of false matches is erroneously applied. No its not billions or trillions before false matches start occuring.

Results first

For completely random 'parthenogenic' profiles , no parents and no ancestral history factored in. Then estimated starts for the effects of co-ancestry. Results in agreement with published results for 6 loci and the remainder agreeing with simulations. 6 loci pre-2000 FSS, UK Caucasian: 9,900 so starting at about 2,000 10 loci FSS, UK Caucasian: 2.3 million so starting at about 500,000 9 loci NIFS, Australian Caucasian: 420,000 so starting about 100,-000 9 loci NIFS, Australian Aborigine: 290,000 so starting about 70,000 13 loci CODIS, USA Caucasian: 20.5 million so starting at about 5 milion

There is still the square law where doubling of the number of profiles quadruples the number of matches. To go any further, to bring into the real world, I need minimum allele frequency to ancestral background correlation data, which is not in the public domain AFAIK. Unknown half-brothers (wrong side of the blanket) reduce the number N even more as also any cross-linking of loci and allleles. General formula for determining the minimum numbers of totally random profiles before the first false match occurs.

For n loci 1..... 6 (9,10,13,15 or any number) and m (valid) alleles at each locus and 2 per locus. So Allele Frequencies are AF1 ..... AFm Let Sn be the sum of the squares of AFs at locus n ie Sn = AF1^2 + AF2^2 +...... + AFm^2 for each n Let Qn = Sn^2 for each n Let p = (Q1 * Q2 * .... * Qn ) [(2-S1) * (2-S2) * .... * (2-Sn)] Then N = minimum number before finding a match is N = SQRT (2/p)

For 6 loci results using UK Caucasian AF data
Locus 	 Sn 	 Qn 	 (2-Sn)
vWA	 0.1938 	 0.0376 	 1.8062
THO1	 0.2195 	 0.0482 	 1.7805
D8 	 0.1974 	 0.039 	 1.8026
FGA 	 0.1341 	 0.018 	 1.8659
D21 	 0.1673 	 0.028 	 1.8327
D18 	 0.1236 	 0.0153 	 1.8764

so p = 5.45 * 10^-10 * 37.2 = 2.027 *10^-8 and N <> 9,900 for 6 loci For 10 loci the extra factors are Locus Sn Qn 2-Sn D2 0.1213 0.0147 1.8787 D16 0.2218 0.0492 1.7782 D19 0.2379 0.0566 1.7621 D3 0.2068 0.0428 1.7932

So new p' = p * (2-S1)(2-S2)(2-S3)(2-S4) * (Q7 x Q8 x Q9 x Q10 ) p' = 2.027 * 10^-8 * 10.56 * 1.752 * 10^-6 = 3.75 * 10^-13 and 10 locus N <> 2.31 million Simulations gave about 1.8 million

Australian 9 loci , for Capital Territory Caucasian Locus Sn Qn 2-Sn D3 .2056 .04227 1.7944 vWA .1861 .03463 1.8139 D5 .3006 .09036 1.6994 D8 .1971 .03885 1.8029 D18 .1205 .01452 1.8795 FGA .1419 .02014 1.8581 D21 .1585 .02512 1.8415 D13 .217 .04709 1.783 D7 .1763 .03108 1.8237

p = 5.525 * 10^-14 * 208.5 = 1.152 * 10^-11 so N <> 420,000

USA 13 loci Caucasian using RCMP data Locus Sn Qn 2-Sn

D3 .2068 .04277 1.7932 vWA .1958 .03834 1.8042 D8 .196 .03842 1.804 D5 .2954 .08726 1.7046 D13 .212 .04494 1.788 D7 .1952 .0381 1.8048 D16 .2468 .06091 1.7532 FGA .1405 .01974 1.8595 D21 .1651 .02726 1.8349 D18 .1279 .01636 1.8721 THO1 .2194 .04814 1.7806 TPOX .3802 .14455 1.6198 CSF1PO .275 .07563 1.725

p = 2.656 * 10^-15 * 1788.8 = 4.751 * 10 ^-15

N <> 20.5 million Simulation gave a figure >10 million

Returning to Australia and Northern Territory Aborigine data Locus Sn Qn 2-Sn D3 .2618 .06854 1.7382 vWA .2129 .04533 1.7871 D5 .2201 .04844 1.7799 D8 .1652 .02729 1.8348 D18 .1312 .01721 1.8688 FGA .133 .01769 1.867 D21 .147 .02161 1.853 D13 .2558 .06543 1.7442 D7 .2586 .06687 1.7414

p= 1.1822 * 10^-13 * 199.2 = 2.3549 * 10 ^-11 N <> 290,000



What about those that have used DNA profiles to be exonerated? Are we freeing people falsely according to your theory? Where do you draw the line?

Certainly you would have to agree that even if what you say is true - it DNA analysis is much better than eye-witness accounts and circumstantial evidence!?

In a perfect world, no one would get falsely accused, nor would any crimes exist - most of us would be out of a job. Life would also probably be very boring and innovations would not be made because the need would not be there.



Followup on Ruelas case This is all getting ridiculous. Yet again quote of trillions. The figure for CODIS 13 loci before false matches occur is 20.5 million, totally random profiles with absolutely no co-ancestry. Factor in the fact everyone has ancestry etc brings that figure down substantially. http://www.mlive.com/news/jacitpat/index.ssf?/base/news- 11/110615430071040.xml

DNA test results still a mystery But chances that DNA found on murder victim aren't convicted killer's are astronomical Wednesday, January 19, 2005 By Steven Hepker Staff Writer Some skeptics doubt a report this week that authorities found the blood of a convicted killer from Jackson on a 1969 murder victim -- when John Ruelas was 4 years old.

But Washtenaw County investigators say blood on the left hand of Jane Mixer, a University of Michigan law student whose body was found in a cemetery, was that of Ruelas.

"I don't think it is a mistake. I think it is his blood," Washtenaw County Assistant Prosecutor Steven Hiller said. "The chances it wasn't him are astronomical."

A state police DNA analyst said the chance of a random match is 1 trillion to one, Hiller said.

Officials followed up the database match with fresh DNA samples from Ruelas with the same results, Hiller said.

"It is odd and a circumstance we want to explain," he said.

The Washtenaw County murder was decades old before DNA evidence surfaced in criminal cases, but police had preserved evidence from the victim, Hiller said.

State police interviewed Ruelas in prison regarding the DNA match. They also have interviewed the man charged with killing the UM student, 62-year-old Gary Leiterman of Gobles. There is no known connection between the two men.

Hiller said Leiterman's DNA was found on the victim's pantyhose.

He declined to discuss the results of interviews with the two men, except to say, "we are still looking."

Ruelas, 40, is serving 20 to 40 years in prison for second-degree murder in the Jan. 25, 2002, beating death of his mother, Margaret.

He had routinely beaten his mother over the years, culminating in what investigators alleged was a brutal beating in their St. Clair Avenue home.

Her face and head were pounded purple, and she suffered 11 broken ribs, making it nearly impossible to breathe, police said.

The Ruelas family was living in Detroit in 1969, Hiller said. The father died in the 1970s. John and Margaret Ruelas moved into a duplex on St. Clair in late 2000 or 2001, neighbors said at the time of the murder.

They previously lived in Battle Creek. He married a woman in 1996 and they divorced in 2000. His ex-wife sought three different personal protection orders against him in Battle Creek, according to court records.

Police said by the time John and Margaret Ruelas moved here, he had battered his mother for years. In 1989, he had held his mother captive in her home in Battle Creek for a week, beating her, police said.

His mother refused to testify against him, and he accepted a plea agreement.

In 1996, she suffered a broken pelvis when she fell from a third- story window in Battle Creek. She said it was an accident.



I'm afraid you're mistaken about the sample being a "simple," "pure" blood sample. This was clearly stated to be a mixed sample of at least two donors, with all the added complexity that fact entails. I am not a DNA analyst, so I am not qualified to argue the statistics with you (I'll leave that to those so qualified). However, I will point out a seeming flaw in your logic if not your math (again, I leave the latter to others). You seem to assume that because a profile is not proven unique that there will necessarily be false matches. That is a non sequitur conclusion, and although I admit I have not been following this thread closely (and so have not digested all of your presentations) I have not seen how your "mathematics shows that there _must_ be false matches occurring." Can you explain for the non-statisticians among us exactly how your math "proves" that false matches "MUST" occur? I know enough to realize that no statistical calculations with any number of loci can ABSOLUTELY eliminate ALL possibility of a coincidental match with more than one person (there is still that "1" in whatever astronomical number), but that by no means indicates that such a coincidental match MUST occur. With sufficiently large statistical probabilities, that possibility becomes so vanishingly remote as to be practically nil.

Further, when you not only consider the statistical probability of one in billions or trillions (or more), but also consider the question of access to the crime scene (i.e., only a limited segment of the population could have access to a given crime scene, not the entire world population), it magnifies the statistics even more, making the probability of a coincidental match in the _relevant_ population even more remote. For example, if a rare profile would statistically be expected in, say, 6 people in the world population, but 5 of those six people happen to live on the other side of the world and have never visited the country the crime occurred in, then within the relevant (local) population, statistically that profile would be expected to be found in only one person, not six. As other list members have pointed out in past discussions, the relevant question is not how many others could share the same profile but rather how many others WITH the same profile could have deposited the sample at the scene. DNA statistics should be considered within the context of all the other evidence and facts of the case, not in isolation. Besides, DNA can only prove a connection between a person and the recovered evidence; it doesn't prove the person committed the crime (there may be an innocent explanation for the connection).

Finally, while I am again not qualified to argue the numbers with you, I could not help but notice that the calculations you presented in the messages I did read concentrated on 9 loci, yet you try to extrapolate the weaknesses you see in those statistics to 13 loci, as if adding four more points of comparison increased the numbers by only 4/9 or 44%. But each additional loci increases the statistical numbers by much, much more than that. I know enough about statistics to understand that using 13 points of comparison instead of 9 increases the statistical probabilities by several orders of magnitude.



The crux of the problem is that forensic scientists, on continually hearing figures like 640,000,000,000 or 844 septillion etc, have got it in their heads that DNA profiles show uniqueness. Once you have, even CODIS databases, in the low millions the mathematics shows there must be false matches appearing. Its just you cannot predict, prescisely, who will be implicated falsely. Just that those with all high allele frequency profiles will be likely 'framed' first. It does not require billions .... septillions. It does not require contamination, sloppy or inept sample handling/processing. I thought it was a pure crime-scene sample of blood not a mixed sample - again fundamental.



There is nothing wrong with DNA evidence that isn't wrong with every other kind of evidence. Heisenburg showed that there is no such thing as 100% certainity. In fact, we have to rely on circumstantial evidence, until we invent a time machine videorecorder and can go back and tape the crime. This argument is purely academic.



Dear Gerrit, Thanks from all of us down under in OZ who also are aware that we are far from perfect....I have always had a problem dealing with the 'super EGO's' that only the USA can belt out with such gusto...!!!! I have never been so happy to be an Aussie in all my life and can't quite believe that these two supposedly professional people would behave like this in a public forum....

Cheers from Oz



Are there cases where DNA alone is used to convict ? I know of many where it has been used to exclude. I don't recall any cases where DNA has been used without some surrounding circumstancial evidence to support it. But a defendent's blood on the body of a murdered person without other identifying evidence, could be enough to convict, I suppose. Really hard to explain its presence to a jury.

"In three of them only Leiterman's DNA was indicated. The other two showed it was a mix of DNA identified as Leiterman's and Mixer's, he said. " I found no reference to what form the 'Ruelas' trace was found. Implicated via database so implication is uncontaminated single trace - AFAIK mixed stains can never lead to a single large database match as usually thousands of possibles. Has there ever been a 46 peak , on 13 loci, two person mixed stain result ? I very much doubt it.



Derivation of formula for minimum number before repeats start occuring. Start with a loaded dice analogy, then convert to the directed pairs situation and finally convert for the more varied locus/allele situation.

Consider a 10 faced loaded dice with weighting such that face 0 or face 1 have a probability of 0.2 each face 2 or 3 , probability 0.15 each and faces 4 to 9 , 0.05 each

Toss 10 times and record the 10 digit number Repeat n times. Determine a number N where a repeat of a previously occuring 10 digit number will occur.

The probability of a random pair of single
digits matching is
Sum of the squares= 2(.2^2) + 2(.15^2) + 6(.05)^2 = 0.14.  
The digits
in each of the 10 positions are independent, so the overall
probability of all 10 digits matching is (sum of squares)^10 ~= 2.893e-9, and call p. 

To generate N numbers, there are N(N-1)/2 pairs of numbers which must all be different to avoid a repeat. If the pairs were independent then the expected number of repeats would be pN(N-1)/2, which will be 1 when N is about 26,000. This estimate for the expected value should be fairly close for N << 1/p. so N = SQRT(2/p) By comparison, if the numbers were unbiased , normal dice, then about 1 repeat in the first 140,000 numbers. It is impossible to predetermine what matches/repeats will occur , just the number of tosses before they start to appear. Doing this on computer gave "0101026021" "1012303012" "3153031131" as 3 pairs of repeats in a 30,000 run. Do another run and they will be different figures and second point is the matching numbers do not exclusively only contain the most common weightings of 0,1,2 and 3 , there is the odd 5 and 6.

Now convert to factor-in directed pairs, the dice are tossed in pairs and the results written down smaller,larger, analogous to 2 alleles per locus.

The factor p now becomes (2 * 0.14^2 - 0.14^3)^5. The -0.14^3 term because 'homzygous' pairs are invariant on directing. eg "3153031131" becomes directed to "1335031113" likes of "1335301131" also becomes "1335031113" A 30,000 run gave 21 , 10 digit directed-pair matches

Now convert to the DNA profile situation and formula becomes

For n loci 1..... 5 (6,9,10,13,15 or any number) and m (valid) alleles at each locus and 2 per locus. So Allele Frequencies are AF1 ..... AFm Let Sn be the sum of the squares of AFs at locus n ie Sn = AF1^2 + AF2^2 +...... + AFm^2 for each n Let Qn = Sn^2 for each n Let p = (Q1 * Q2 * .... * Qn ) [(2-S1) * (2-S2) * .... * (2-Sn)] Then N = minimum number before finding a match is N = SQRT (2/p)

As in the DNA profile situation you cannot predict what the matching digit numbers will be , just that they will consist of the more common alleles. Someone with a number of rare alleles is very unlikely to ever have an unrelated match. With emphasis on unrelated. If fathers "play away" and there are unknown half-siblings with some rare alllele also appearing in such a database then that changes matters.

Summary for minimum number of profiles for the totally artificial situation of 'parthenogenic' profiles with no 'parents' all totally randomly generated 6 loci pre-2000 FSS, UK Caucasian: 9,900 10 loci FSS, UK Caucasian: 2.3 million 9 loci NIFS, Australian Caucasian: 420,000 9 loci NIFS, Australian Aborigine: 290,000 13 loci CODIS, USA Caucasian: 20.5 million

The above and below in agreement with simulation results.

Calculated minimum numbers for sub-sets of profiles like mine of > 8 per cent AFs , also for >3 per cent ,Codis case. 6 loci UK Caucasian for >8% then 2,400 10 loci UK Caucasian for >8% then 280,000 9 loci Australian Caucasian for >8% then 44,000 9 loci Australian Aborigine for >8% then 21,400 13 loci USA Caucasian for >8% then 2 million 13 loci USA Caucasian for >3% then 10.2 million

All my alleles have an AF greater than 8.6 %, it is that subset ie all >8% that are in most danger. I have on order, from the British Library, a publication that may allow me to put a minimum AF distribution to a population to discover what proportion of a population substructure/co-ancestry would have minimum AFs of 8%, proportion 5%, 3% etc

Everyone's DNA profile is rare until it has a match in multi-million databases. In my definition of "rare" an individual would have a number of rare alleles, say sub 1 percent AF. Then his chance of false implication is much much less than someone like myself. I don't have a Lithuanian or Iroquois grandparent to take me out of the background high AF genepool and this Damoclean situation. Now false matches are appearing in these large databases it will occur with more and more frequency. There are now millions of profiles in these databases and thousands of match-check searches a week. The cross-over point has now been passed where there is no guarantee that a consequential match is real rather than false. Re my last post on derivation of false match formula my 13 times table is rusty and should have referred to 4 * 13 = 52 peaks and not 46

The blood evidence incriminating John Ruelas was stored away 36 years ago. That historic evidence and his present day personal samples have been separatly tested and repeated again. There is no doubt that the DNA profile matches - the problerm is forencsic 'scienmtists' who have a mindset that believes false matches are impossible because they keep hearing, and repeating in court, nonsensical numbers like 43 trillion to one ... even up to 840 septillion chances against such events. Equally damning there is no validation research into the non-transmuteability of samples stored at ambient, or frozen for that matter, for 30 years or more.

When OB/GYN physician office labs were found to be using there grandmothers to view pap smear slides in the 80's, the Clinical Laboratory Improvment Act was passed in '88. Unless similar standards in education and certification are enforced , human error will always be the greatest factor in mistaken test results.



Keep in mind that the vWA results as YOU see them are YOUR opinion and no one elses on this planet. I have stated to you at least once that YOU CANNOT MAKE ANY JUDGEMENT REGARDING THE CMJ article PLOTS. Since you put forth a fundemental tenet of science, let me give you another. Sceintist don't make statements (such as yours) without interpreting all the data. Yet you continue to assert your opinion of the CMJ data without all the facts. Not to mention the fact you obviously have no training or experience which would qualify you to do so. You have clearly read just enough information on the subject to make you dangerous.

With respect to reproduciblity... the science is reproducible and all the validations and papers written on the validations demonstrate as such. So your statement is baseless. Stutter does not mean a properly trained analyst can't interpret data. You are wrong... period! Leave this science to those who are trained to perform it.

Regards,

Ken

P.S. For the love of God can we please end this thread. The horse is dead.

Dear Ken, It is best to ignore this guy and continue your belief in what you know. It is so very tempting to blast him when he types with such ridiculous statements, but that is taking the bait and letting him run with it. The delete" button is good way to deal with him.

Are you saying electrophoegrams are inadmissible in court ?. You would like, no doubt, the situation where just sets of numbers are presented in court after being fiddled, sorry interpreted.

I repeat the science is not reproduceable. from FSI 143 (2004) 5 profiles in 2055 individuals, not mixed stains, were falsely homozygous on vWA
3 in 2055 false H on D8
2 in 2055 false H on FGA
3 in 2055 false H on D18
2 in 2055 false H on D5
so 0.7 per cent wrong due to false homozygosity

I am not aware of the validation studies into falsely included stutter. Please inform me where you've found that research to show 0 per cent error rate on stutter.

I agree there are some very dangerous people around this subject. I have recently been contacted by someone related to a prisoner denied parole in the UK because his DNA profile matched a cold-case DNA profile from 15 years ago. The proveable fact he was abroad at the time of this historic crime is ignored because the UK's dangerous characters have a mindset that places DNA 'evidence' above normal exculpatory evidence. Having been contaminated by repeated hearing, if not saying, false match figures like 840 septillion to one. No court case, just continued prison sentence, because the UK's dangerous characters have deemed him guilty with no other evidence whatsoever.

Mirroring this case in USA http://www.sltrib.com/utah/ci_2491514 19 Dec 2004 <...> Rudy Michael Romero was about to be paroled for an armed robbery conviction when he was linked to a series of rapes along the Jordan River Parkway in the early 1990s. Based on recent DNA tests, the Utah Board of Pardons and Parole revoked Romero's July parole date and ordered he serve at least another 25 years. While DNA cases that free prisoners have become common, the Romero case is raising eyebrows in the legal community - though nobody is rushing to his defense. Utah's parole board acknowledged it has entered "uncharted waters" by keeping Romero behind bars based on evidence of crimes for which he has not been convicted. Romero will never be tried for the Jordan River rapes because the four-year statute of limitations has expired. But the DNA evidence was compelling enough for parole board members to deem Romero a sexual predator who would pose an "unacceptable risk" to the community. Parole Board Chairman Michael Sibbett says that because Romero is serving a five-years-to-life term for aggravated robbery, the board can keep him locked up for the rest of his life. End Quote

As I am not a DNA analyst I am not knowledgeable about the effects and distribution of the phenomenon known as "stutter," so I can not and will not attempt to debate that with you (I again leave that to others, if there are any with any patience left). However, the very fact that you seem to expect a total absence of variance in a scientific measurement clearly demonstrates how very shallowly you understand the science you so passionately declaim (and prevaricate about). I am somewhat amazed that you can be impressive in your mathematical musings, yet make such ignorant statements about the larger picture. This suggests an inherent (and insurmountable?) prejudicial bias in your viewpoint that is blinding you to some very basic scientific maxims.

Let me try to explain where you've gone astray this time. Science is not as straightforward as simple mathematics. There is variance in ANY measurement of any kind, because no measurement can be perfectly exact. A measurement can be accurate but not precise, precise but not accurate, both accurate and precise, or neither. Accuracy is determined by comparison with known standards, and precision is calculated based on the variance observed between successive measurements. Therefore the concept of reproducibility is relative, not exact. Scientific measurements are not stated with absolute certainty but rather within a set of given "confidence limits," or "degrees of uncertainty," e.g., a weight might be expressed as "125.045g +-0.006g." I believe this is what others were trying to tell you when they spoke of having to interpret the raw data to determine if and where stutter occurred, and how it might affect (or not affect) the results. Simply because a predictably variable phenomenon like stutter occurs randomly in a measurement process is no indication that the method is unreliable or "unscientific." Variation is normal and expected in any measurement process. Such phenomena are studied and characterized, so that they can be accounted for in the interpretation of experimental results. This is why expert human interpretation is an essential ingredient in any analysis.

If you find it difficult to grasp or accept the inevitability of measurement variance and/or the difference between accuracy and precision, try an experiment. Put away your calculator for the nonce and pick up a yardstick (or meter stick); then use it to measure the length of a football field and see if you ever get exactly the same figure twice, down to the inch or centimeter (you won't, because there will inevitably be some variance in exactly where you place the stick each time in the many placements needed to measure the length of the field). Does that mean the measuring stick is unreliable? No, it does not. The yardstick may be exactly 36 inches (or the meter stick exactly 100 cm) in length and it certainly doesn't change during use, therefore it is accurate; and if your use of it is skillful, so will your measurements be accurate. Yet you will naturally and unavoidably have some variance in your application of the stick to the field and so will get varying totals each time you sum your group of measurements. This is measurement variance or imprecision, and it is inevitable. Do enough repetitions of these groups of measurements, and you will be able to determine the mean, degree of variance and standard deviation of your total set of measurements (you can pull out your calculator to do this), and so will be able to accurately state the length of the field within those given confidence limits (i.e., the mean will be accurate within the stated degree of precision). For example, you may come up with a figure of something like 99.53 yards, plus or minus 0.9 yards. That is a statement of both the accuracy and precision of your conclusion.

This is how scientific measurements are determined and described.

And with that, a good weekend to all, and to all a good night!

I'm glad to see you are checking primary sources.

But it pales into the background, for errors, compared to this more general study that should also be consulted Int. J. Legal Med. 2004, 118:83-89 The Gednap blind trial results from 2002 over 30 European countries. It gives a good idea of the sum of errors including transcription, misinterpretation etc. Forgetting for the moment the forensically artificial use of 50/50 blood stains, also blind rather than double blind ( they knew they were being tested ). On the other hand there were, deliberately, a couple of hard inclusions FGA (42.2) in with 21,22 and 23 and THO1: 8.3,9,9.3,10 which often needed human interpretation.

I've not been able to get the GEDNAP protocols and the published table on p84 does not state the number or average number of samples sent to each lab. The earlier 1990s tests, also in the table, were certainly tests per locus and from the text there was at least 5 stains sent out. Year 2002 results for 136 different European labs and selected from a pool of 17 loci there were 30,479 (single locus rather than multi-locus ?) tests, giving an error rate of 0.4%. My interpretation is - one or more wrong alleles in each of these single locus tests recorded as one failure. But as 50/50 contributor tests it is also a reasonable approximation to expected single contributor profiles errors. If anyone is aware of a similar interlab test for single samples I would be pleased to get the reference. From the text it was not possible to determine if they were all mixed samples or the labs knew this in advance. So scaling to multilocus situation and FSS 10 loci would be something of order 4% of all profiles erroneous in one allele and 5% of all profiles for CODIS. From an earlier discussion, and consensus, on this group there has to be 20 matching FSS numbers or 26 in CODIS before declaring a match between crime-scene and database. Only fair because choosing ANY 9 from 10 plus one of the remaining pair increases the false match probabilies by very large factors, let alone for CODIS.

As I am not a DNA analyst I am not knowledgeable about the effects and distribution of the phenomenon known as "stutter," so I can not and will not attempt to debate that with you (I again leave that to others, if there are

I keep being told that stutter is recognisable if given the raw data, whatever that is compared to an electrophoreogram unless they just mean skewness in the printing process can displace the traces from the ladder on the original straight off the machine plots. No one is saying what the signature or characteristic of a stutter trace actually is, compared to a real allele trace. A very simple question I would have thought - is it breadth of trace, sharpness of peak, off-ladder response always tied to a specific on-ladder allele ?. Put simply what are trainee analysts told to look for ?

So for those professing to be knowledgable here, what is wrong with the following definition ? It seems fair enough to me - but what do I know.

http://forensicdnaconsultant.com/Glossary.htm Stutter- an artifact of STR amplification, in which the n-1 allele (n is the true allele; n-1 is the true allele minus one repeat unit) produces a signal that is 5-10% of the peak height of the true allele. For some loci, this can be as high as 20%. Stutter peaks can rarely occur at the n-2 and very rarely at the n-3 position.

Returning to http://www.cmj.hr/2003/4403/18DROBNIC.pdf p351, Fig 1, Plot B, 2 in from left of bottom line the unlabelled anomalous vWA peak would appear to obey the n-1 or n-2 or n-3 rule as on the lower weight side. But to my reading it is way above 20% of 15,16 or 17 peak heights. Also without extraneous input what marks out this vWA(*) peak as being an artiface, rather than a real allele? Still everyone keeping quiet on this black art.

I agree with Adam. It is also important to remember that Paul feels that these little exchanges are part of some "peer-review" (his words - see the bottom of http://www.nutteing2.freeservers.com/dnapr.htm) to validate his agenda. You're never going to have an open discussion where Paul sees the other point of view.



Please quote correctly "'peer reviewed'" not "peer reviewed" or is the difference too subtle. Or is it again two nations divided by a common language ?



Here is the response from the paper's author...

"Dear mr.Howard,

if you look carefully the electropherogram of AmpFlSTR SGM Plus, you will see no extra peak at vWA locus in Figure 1 plot A, this extra peak you mention (Fig.1 plot B) is result of pull-up from the other color in yellow because the concentration of DNA used in PCR was to high (RFU is between 4000-6000, but recommendation is 1500 to 2000).

best regards, katja Drobnic"

So as Michael Coble stated, it is pull-up from D3.

So Mr. Nutteing, in all fairness you should add a correction to your website's mention of this article. It should state that you are dead wrong, there are no "extra" peaks that can't be interpreted, and there is no malfeasance in the reported case. I would just delete all mention of the article from your site a few days after the retraction is posted.

I hope this matter is now completely resolved.

Well I, at least, have learnt something. It would be an excellent test-piece for a trainee analyst, if it was not already on the internet.

So a rider should be added to this definition of stutter http://forensicdnaconsultant.com/Glossary.htm Stutter- an artifact of STR amplification, in which the n-1 allele (n is the true allele; n-1 is the true allele minus one repeat unit) produces a signal that is 5-10% of the peak height of the true allele. For some loci, this can be as high as 20%. Stutter peaks can rarely occur at the n-2 and very rarely at the n-3 position. Rider: The reference to 10 to 20% factors only relate to a reference sample situation. With exagerated amplification, to bring up minor contributor peaks, then any stutter could be exagerated disproportionately, way above 20%.

Or is the consensus that this CMJ vWA(*) was not stutter at all but bleed-through ?

Returning to the CMJ case adapted for the more normal situation of a mixed stain sample, with strong major/minor differentiation and just a victim reference sample. So just plot 1B and Figure 3A in effect (ignoring amelogenin ). Then as far as I can see the only indication in that case of vWa(*) stutter/anomaly would be specifically the coincidence of this vWA(*) with D3 (18) and D5 ( 12) which I certainly didn't spot and a general caveat concerning over amplification. IMHO an over-worked analyst in that circumstance may have declared that the suspect would have this spurious vWA(*) allele. How many analysts, routinely, have the benefit of cross-referencing between Power-plex and SGM+ determinations ?

DNA matches & exclusions/Where do you draw the line?

While Paul only focuses on the problems with false accusations (due to poor analysis - not fault of the premise), should someone not point out all the cases that are reopened for DNA analysis. The defense (defence?!) requests DNA analysis to overturn the conviction done before DNA was so frequently used. Many people have been released based on this new DNA evidence. By Paul's theory, many of these were released without true cause. If DNA matches are not consistently correct, why would DNA exclusions be correct? Should we go back to the age before DNA analysis and let falsely accused people get convicted due to circumstancial evidence or ABO typing (or similar technology)? If the statistical analysis is wrong in one case (DNA) would it not be wrong in another (ABO blood typing)? Blood typing uses statistics to determine matches and exclusions - although not on such a grand scale. Both technologies should be treated similarly. So if we cannot use statistical analysis in our search for guilty parties, what are we left with? Eyewitnesses? The proverbial smoking gun? Confessions?

Statistical analysis said that my fiance would survive about 5 years after treatment - the fact that he lasted only 8 months from diagnosis does not mean the statistics were wrong. It merely means that statistics cannot predict the future. There are always 'outliers' I was told by my statistics professor. There are exceptions to almost any 'rule.' My fiance's genetic predisposition for melanoma was statistically negligible, but he contracted it nonetheless. Are those statistics wrong as well? Where do you draw the line, Paul?

IMHO - this is all poppycock. Statistical analysis may not be perfect, nor may DNA analysis, nor may DNA analysts, nor any branch of forensic science; they are better than incomplete analysis.

I hope for the sake of society that you do not work in the criminal field. I find your attitude insufferable and inexcusable. However, you are not the exception, sorry to say.

No, we do not live in a perfect world. However, if DNA is found to be objectively imperfect then it should be treated no differently than a hair found at a crime scene. It should be given no more credence than any other "circumstantial evidence". It should not be allowed to pass the Kelley-Frye test.

As conservative as I might be I do believe it is far better to let ten (10) guilty people walk free than to wrongly incarcerate one (1) innocent person regardless of the nature of the crimes involved. That is one very good reason why the United States of America is, by far, superior to all of the other nations of this world. Let's try to keep it that way.

Greetings from Belgium, whose inhabitants know it's imperfect.



I find *your* attitude insufferable and inexcusable. You seem to be jumping to conclusions without any facts - just an instinctual dislike of me apparently. I'm merely making a point/asking a question, yet you pounce on me without a second thought (or dare I say even reading the entire email). The point being - if people are being falsely accused, people are also being falsely exonerated.

Has DNA been found to be objectively imperfect? To my knowledge all 50 states here in the US, most (if not all) European countries, places in Africa, basically all around the world DNA is accepted as a high quality means of identifying perpetrators.

It is my belief that people should not be falsely accused nor falsely exonerated. If this is happening (which Paul has not proved by any means) then DNA analysis does need to be called into question. However, until this is the case, Paul's theories are just that - theories. Very few inmates will acknowledge that they commited the crime in question - however, in most cases the system worked properly in incarcerating them - When pressed closely, many of the inmates will tell one another or their case-worker that they were correctly convicted.

DNA analysis has been extensively used by defense attorneys to exonerate their clients after they've been convicted. It is unfortunate that innocent men/women are convicted, but as I said previously - this is not a perfect world. However, if DNA analysis is being used to exonerate falsely convicted people - DNA analysis was probably not used to convict them. Therefore, DNA analysis is doing just what you want it to - it is ensuring that those who are convicted are truly responsible for the crimes they are accused of.

I am a forensic biologist - a good one (just as my supervisor)! I do my job and will go above and beyond the call of duty. Something of which you have no knowledge. Could it be a guilty conscience speaking for you? My analysis of evidence is very conservative and correct. I will never say something is so that has not be thoroughly tested - and even then, I make my statements very conservative (not "Human blood of type blah blah was found on Exhibit blah blah which completely matches Suspect blah blah).

However, I believe that the scientific community as a whole and the forensic science community in specific has thoroughly investigated all the tests that are currently used in medicolegal situations. I do not question my phenolphthalein results because it has been tested and retested and accepted by the scientific community and forensic community (defense attorneys included). DNA is still fairly new, but still a sound science. Innovations will take place and make it more accurate, easier to accomplish, cheaper to perform, etc.

By the way, previously you used similar language to object to my spelling correction of Paul (defense and defence) (you apparently didn't read that entire email either because no mention was made of Paul's error in calling dyslexic's "sloppy minds"). You indicated that I was being closed-minded and superior because I was only acknowledging the American spelling. However, at the end of this most recent tirade you say you think American's are superior because "the United States of America is, by far, superior to all of the other nations of this world." This certainly doesn't sound like you are being open-minded. Maybe you should be consistant in your opinions and practice what you preach. Maybe you should avoid personal attacks altogether and stick to the facts and failing that - just avoid reading my emails if they bother you so.

This is an open forum for discussion of forensic-science. I am discussing forensic-science and asking questions of Paul to try to understand his viewpoint. Before you attack - you may want to thoroughly know your subject and what is being said.



I mprisoned by DNA - freed by ABO blood groupings ?

So it goes on - Australia this time. You couldn't invent this stuff and be believed. http://www.heraldsun.news.com.au/common/story_page/0,5478,12051494% 255E1702,00.html Quote Murder pardon being sought By Nikki Todd 25jan05 A MAN convicted of the murder of a British waitress on a remote Great Barrier Reef island more than 20 years ago could find out within weeks whether his petition for a pardon has been granted.

Sydney businessman Wayne Edward Butler was jailed for life in Queensland in February 2001 after DNA evidence linked him to the murder of Celia Natasha Douty, 41, on Brampton Island in the Whitsundays in 1983. Ms Douty's bashed body was found in September 1983, in scrub land behind a beach where she had been sunbaking.

A red towel draped over her body bore blood and semen samples which a jury almost two decades later agreed was linked through DNA evidence to Butler.

But Butler, who was holidaying on the island with his wife at the time of the murder, maintained his innocence throughout his trial and subsequent appeal.

Now 61, Butler has lodged a plea for pardon with Queensland Governor Quentin Bryce.

The pardon is being considered by the state's Crown Solicitor, with a recommendation expected to be delivered to the Governor within four weeks.

The pardon is considered Butler's last resort, with none of the 55 other petitions lodged by prisoners in the past decade in Queensland proving successful.

Butler's pardon application is based upon new evidence by forensic scientist and blood group specialist Professor Barry Boettcher, who questions the validity of results found by the Queensland government's forensic lab, the John Tonge Centre.

Prof Boettcher, who has been involved in high-profile cases including the exoneration of Lindy Chamberlain and the Peter Falconio murder case, believes Butler should never have been convicted, claiming his blood group did not match the semen sample.

"It is my opinion that, since the ABO blood grouping of the semen stains excluded Wayne Butler as being the donor of the semen, there had to be an error in the DNA results," Prof Boettcher wrote in his final report, according to this week's Bulletin magazine.

The Bulletin article says Prof Boettcher is convinced, after examining information gained via Freedom of Information, that Butler's test tubes were mislabelled at the John Tonge Centre.

Butler's sister Alison Butler said her brother did not hold much hope he would be released.

"I don't think Wayne dares to hope," Ms Butler told the Bulletin.

"He had faith in the system. He wanted to go through the system because he thought he would be exonerated.

"He was suffered a wrongful conviction because of a bungle in the laboratory and it has wrecked his life." End Quote

Chimeras

Blaschko lines are chevron type alternating patterns that appear in skin pigmentation associated with chimera

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=2667350 Am J Hum Genet. 1989 Aug;45(2):193-205. Quote Association of pigmentary anomalies with chromosomal and genetic mosaicism and chimerism. Thomas IT, Frias JL, Cantu ES, Lafer CZ, Flannery DB, Graham JG Jr. Department of Pediatrics, University of Nebraska Medical Center, Omaha. We have evaluated eight patients with pigmentary anomalies reminiscent of incontinentia pigmenti or hypomelanosis of Ito. All demonstrated abnormal lymphocyte karyotypes with chromosomal mosaicism in lymphocytes and/or skin fibroblasts. In seven the skin was darkly pigmented, and in all of these seven cases the abnormal pigmentation followed Blaschko lines. The literature contains at least 36 similar examples of an association between pigmentary anomalies and chromosomal mosaicism, as well as five examples of an association with chimerism. The pigmentary anomalies are pleomorphic, and the chromosomal anomalies involve autosomes and sex chromosomes. The pigmentation patterns are reminiscent of the archetypal paradigm seen in allophenic mice and demonstrate the clonal origin of melanoblasts from neural crest precursors. Patients with anomalous skin pigmentation, particularly when it follows a pattern of Blaschko lines, should be appropriately evaluated for a possible association with chromosomal or genetic mosaicism or chimerism.

End Quote

DNA testing question

My copy of FSI article 112 (2000) p151-161 is in paper form only, after application to the British Library technical journal requests. In UK terms 1.50 GBP plus 0.10 GBP per page I don't know what the LoC charges would be but I do know that a lot of USA academics use the BL, Boston Spa , Yirkshire UK facility in prefernce to the USA system IIRC for reasoins of turn around speed rathe rthan costs.

AFAIK all countries have a similar system for otherwise expensive subscription access. Certainly US, UK and Oz do

I returned to FSI 112,2000, 151-161

Happened to notice in the sub-study for cross-validation of different somatic samples from same individual.

"Any stutters that occured in the profiles were below 10 per cent of the associated allele and were not prevalent in any sample type." I would suggest this troublesome anomalous vWA(*) peak in amplitude or area terms is supstantially more than that declared 10% threshhold. Translating to a hypothetical single contributor sample then if homozygous (h,h) in whichever allele causing the stutter, I would posit the 'interpretor' would have declared a result vWA (*,h) not vWA (h,h)

Also in that FSI 112 study the nearest I've seen to long term validation research. One 17 years old blood sample stored at ambient temp and RH. High molecular wt peaks especially D18 and D2 were degraded almost to mush-level compared to the remainder also attenuated but useable. No mention of whether this adult was traced and typed for migration/anomalies due to UV damage or whatever. I find it absolutely abhorent that people are being incarcerated on 20 or 30 yearold DNA 'evidence' with no validation studies into this as far as I can find ,qv (Guthrie cards thread ).

Returning to FSI 143 (2004) 47-52 showed 5 samples in 2055 having false homozygosity So once again in routine, this time single contribution samples how does the person doing the 'interpretation' handle that. Results by these (French) analysts/interpretors were 2 homozygous in 15 and one each at 16 , 17 and 18

As far as I can see only discovered as false homozygosity precisely because it was a validation study using 2 different systems. True ( or at least different on othe rsystem) vWA results were (15,17), (15,18) ,(16,18),(17,18), (18,21) all falsely homozygous on the low allele.

I seem to have made an error on the D21 result , the others are correct, for Bobby the chimpanzee and DNA profile using 'human' SGM+ kit; Amel. X,Y ; D8 (10,12) ; D21 (23,24) ; vWA (12,12) ; FGA (17.3,23.3) ; D3 (14,14) ; THO1 (6,7) ; D2 (21,22) ; D16 (9.3,9.3) [ 8 +1 loci ]

From same table 1 on page 156 is an unnamed female gorilla DNA profile with null alleles on D21 Amel. X,X; D8 (7,7) ; vWA (17.3,17.3) ; FGA (27.3,32.1) ; D3 (16,17) ; THO1 (4,7) ; D2 (22,24) ; D16 (11.3,12.3) [ 7 + 1 loci ]

[ Remember just 6 loci was considered perfectly adequate by UK FSS 'scientists' to be able to quote uniqueness figures of 1 in 37 million in courts, to prosecute, during the 1990s. ]

Other primates had many null alleles. Of other more distantly related species the 'best' performing was a domestic cat giving two responses one peak on D8 12.1 and one peak on D3 19.3



Only 113 years late

http://www.baltimoresun.com/news/nationworld/bal- te.prints21feb21,1,986783.story?coll=bal-nationworld- headlines&ctrack=1&cset=true

Justice institute seeking answers on the reliability of fingerprints Study urged on quality of evidence, comparisons By Flynn McRoberts and Steve Mills Chicago Tribune Originally published February 21, 2005 Four years after scuttling a study into the reliability of fingerprinting, the research arm of the Justice Department is seeking answers to fundamental questions about the granddaddy of forensic science. The National Institute of Justice recently called for researchers to explore such crucial issues as how to measure the quality of fingerprints lifted from crime scenes and the accuracy of comparisons made by law-enforcement examiners.

The research solicitation seeks to "provide juries with increased information about the significance and weight of fingerprint evidence" and also to create tools "to improve the fingerprint examination process," said Catherine Sanders, spokeswoman for the Office of Justice Programs, which includes the institute.

The agency's decision is the latest example of an unmistakable shift in the previously defiant world of fingerprint experts. Until recently, they had pointed to nearly a century of convictions in U.S. courts to dismiss calls for a closer examination of their discipline.

The institute's solicitation is "very significant because it's recognizing that there is an area that needs to have research done, and they're willing to step up to the plate and fund it," said Ronald Singer, president of the American Academy of Forensic Sciences. "What I think NIJ is hoping is that they can fund the research that will validate the process and answer a lot of the questions."

Across the nation, law-enforcement and forensic officials are beginning to acknowledge the need to show whether science supports the expert witnesses whose opinions have long been accepted as gospel in American courts.

The broader reassessment of fingerprint comparison is largely being driven by a series of high-profile errors committed by examiners, including their role in the wrongful conviction of Stephan Cowans, a Boston man imprisoned for six years after a bogus match linked him to the shooting of a police sergeant.

A few months after Cowans' release last year, an even more embarrassing mistake occurred when the fingerprint world's elite -- examiners at the FBI lab -- falsely connected Brandon Mayfield, an Oregon lawyer, to the Madrid train bombings through a print found near the scene.

For several years, the National Institute of Justice has sought to walk a fine line over fingerprint comparisons -- seeking to bolster the scientific foundation of a time-honored discipline, without admitting weaknesses.

Calling for any research gives ammunition to defense attorneys who can suggest that the very need for such a study shows that the discipline is not entirely reliable.

Robert Epstein, a federal defender in Philadelphia, did just that several years ago when his client was charged in a robbery. In one of the only cases where a judge has told prosecutors to prove the scientific validity of fingerprint comparison, the FBI asked crime labs across the country to help the bureau convince the judge, in part by examining fingerprint evidence from the case.

While most examiners agreed with the FBI's conclusion that the defendant's prints matched those found on the getaway car, 17 examiners in nine states were unable to make an identification -- underscoring that the discipline is much more subjective than many fingerprint experts have acknowledged.

After receiving the conflicting responses, one of the FBI's top fingerprint experts asked the dissenting examiners to take another look, with the help of some FBI enlargements of the prints in question.

"These enlargements are contained within a clear plastic sleeve that is marked with red dots depicting specific fingerpint characteristics," wrote Stephen Meagher, chief of the FBI lab's latent print unit, in a June 1999 letter. "Please test your prior conclusions against these enlarged photographs with the marked characteristics."

(Contacted last week, the FBI declined to elaborate on the letters, saying they were part of the public record.)

Three months after Meagher's letter, the National Institute of Justice approved a call for research into fingerprinting, only to eventually let it die amid an uproar from police and prosecutors.

But continuing questions about the reliability of fingerprint comparison and the experts who practice it increasingly are prompting crime labs to re-evaluate how they do their work.

The FBI has long left it up to individual examiners to determine whether they have enough points of comparison -- among the loops, whorls and arches that make a fingerprint -- to identify a match.

But the bureau is now considering imposing guidelines on them, including the hundreds of examiners who evaluate tens of thousands of prints a day at the FBI's fingerprint database headquarters in West Virginia.

"Probably within the next year, we're going to set our own standards - - a minimum number of points needed to declare a match," said Charles Jones Jr., a fingerprint examiner instructor at the FBI's West Virginia facility.

Asked why the bureau was considering the change, Jones said: "I guess the Mayfield case was an eye-opener for everybody."

Noting that the examiners at the FBI lab outside Washington, D.C., have "always been the cream of the crop," he added, "If those guys can make a mistake, so can we." End Quote

false positive ten locus dna matches, more or less



I'm doing some research and trying to find false positives such as Peter Hamkin or the Goettingen case where there have been false positive dna matches at ten or so str loci. I am especially looking for news reports, journals, or other published sites besides websites by afficionados.

All help would be most appreciated.

Someone with my own concerns - very much a rarity. I don't know how many loci, as that sort of info does not seem to leak into the general media. The 'Watters' one was 6 loci. All of the below cases were considered matches sufficient to arrest and seriously inconvenience to say the least - except the ones with the perfect alibis of course. If the news-agencies have deleted any of the following links then I have archived them myself, but you will have to email me for that. Notice the followup investigations , if any, are never released into the public realm - I wonder why. I am the only person who has reported this material in its entirety. Le Monde published a piece that could well have substantially been derrived from my material but that is all in the established media public or likes of FSI or IJLM. Anyone know of the followup to the John Raelas 4 year-old 'rapist / murderer' ?

Obscure because supressed. The FBI expunges false matches from databases before alllowing others to look "Budowle testified (2) that all the matches have been edited out of these databases and that this removal is justified because it is not possible for two individuals to yield identical profiles when as many as seven probes are used." Science,Vol 256,26 June 1992 p1743
Author Patrick J. Sullivan

A Nick Davies crime/feature reporter of the UK national newspaper The Guardian was going to write a piece but something/someone (D-notice ? ) warned him off.

In the space of one week Special Branch closed down 4 of my web-sites to suppress. I had to contract back to my Russian site. They had to arrest me on a b.ll.cks charge in a completely failed attempt to keep me quite. 3 of those 4 sites regained and something like 9 more started in direct response to this corrupt form of attempted censorship.



Please feel free to update but I doubt there is any change in principle - non disclosure. The UK FSS are just the same in 2004 / 2005 - total non-disclosure.

More complete quote from the original letter Fom Science,Vol 256,26 June 1992 p1743
Author Patrick J. Sullivan


Title : DNA Fingerprint Matches I am writing to comment on two aspects of the report " On the probability of matching DNA fingerprints " by Neil J. Risch and B. Devlin (7 Feb,p717) . Risch and Devlin searched several large databases to determine whether there were any samples with matching patterns across a nummber of gene loci. They found " the probability of a matching DNA profile between unrelated individuals to be vanishingly small....." Last summer I was trying a Federal Bureau of Investigation (FBI) case, Minnesota v. Johnson (1),and examined three FBI databases,C-3 (Caucasian),B-4 (black), and H-3 (Hispanic). During my examination,I discovered 25 apparent matches. Before my examination ,the existence of these matches had been known by only a few individuals connected with the FBI. Bruce Budowle of the FBI subsequently testified in Minnesota v. Johnson that he was aware of these matches and that they had been discovered when the FBI examined its database with its computer matching program. The FBI was able to verify that most of these matches occured because the Texas College of Osteopathic Medicine submitted more than one blood sample from the same individual. One false match was the result of sample handling error. The FBI also discovered three sets of matching samples from Florida. These samples were from the black and Hispanic databases. The FBI was not able to identify that the Florida matches were the result of duplicate submissions from the same individual or of submissions from identical twins. Budowle then asked Cellmark Diagnostics (German- town,Maryland ) to examine the matching samples. Its probes also yielded unclear results. The Florida matches were then deleted from the databases,even though there was no explanation for their occurance. The FBI again revised its databases in January 1992. The new databases are designated C-4,B-5, and H-4. Budowle testified (2) that all the matches have been edited out of these databases and that this removal is justified because it is not possible for two individuals to yield identical profiles when as many as seven probes are used. My first point is this: Of what scientific value is a paper that seeks to draw any conclusion from the fact there are no matches in a database when the matches have been removed from the database before the analysis is done? The FBI's removal of matches from its databases before giving them to outside scientists guarantees that those scientists' conclusions will support the FBI's "self-fulfilling prophecy." This is not an isolated practice. Budowle testified in United States v. Yee (3) that the FBI ran its match program over its South Carolina black database and found a large number of matches. The FBI's record- keeping was such that it could only speculate as to the cause of these matches. Again,the FBI removed them from its database. End Quote



These are interesting points. The problem remains that in countries like Canada, for instance, there is no uniform policy mandating forensic labs or prosecuting attorneys to use 13-locus matches only in court. As a case recently showed in Chicago, this can lead to false allegations or arrests.

I am dealing with a case where there is a nine-locus match and the prosecutor is refusing to assist in having the evidence sample tested at 13 loci. This case also concerns the possibility of fraternal contributors. I'm hoping to raise the awareness level of the possibility of nine or ten locus matches, whether between brothers, relatives, or non relatives.

If anyone can assist me, I'd be most gracious. I have followed many of the links in Paul Nuetting's website. As a result, however, I am still looking for documented nine or ten locus matches that were cleared up by more discriminating tests. I am also looking for information documented in news, papers, official websites and the like as to what the standards are in European or other country forensic databases regarding the number of loci used for their records. I know that England is 10. I've heard that Italy is 13. Some reliable sources are needed.

Thanks very much for all responses,

You will find its universally accepted within forensic science Oz 9loci, UK 10 loci or USA 13 loci that you do not get false matches. They have so blinded themselves quoting nonsense unfounded false match probalities such as 640 billion .... 840 septillion. They always say it must be cross-contamination or some such impondrable. I am in contact with a relative of a UK prisoner denied parole because his DNA profile matches a crime-scene profile obtained 15 years ago despite him being abroad at that time.



You would think it was one of the most fundamental of researches to be published in FSI or whatever. This was the last disclosure on false matches back in 6loci days. Forensic Science International 95 (1998) p30. Concerning data in the UK DNA database as of 04 October 1996 when there were only 6311 samples from the London area and 573 from the Cardiff area. "A small number of unresolved duplicate pairs of profiles were present in the regional data :10 pairs within the London region and 1 pair in Cardiff. The most common cause of duplicate entries is the use of aliases by suspects who have been arrested on several occasions. For administrative reasons ,it is not always possible to resolve such duplicates by exhaustive police investigation."

It could not be simpler to cross-correlate with mug-shots or dermal fingerprint database to check for aliases. I wonder why they didn't or at least publish the results.

Please contact any relevant persons in the FBI , FSS, NIFS etc to run their match checker over the arrestee database and disclose the numbers now the totals are in millions

They only get reported in the mass media, never in forensic science journals. I had it from a leading forensic scientist that this Prof Chaseling 7 loci false match in 5,500 and other such matches was to be published in likes of FSI but never was (in archive as newspaper site is now subscription) http://web.archive.org/web/20001025074133/http://www.smh.com.au/news/0004/22/text/review8.html Don't want to bite the hand that feeds it. Its all about clear up rates for minimum expense. No matter prosecutions via false matches, it is 'justice' on the cheap which is the main aim.

I wonder how many FF database custodians are actually privvy to the number of unrelated (non- alias) 10 loci matches in that section of the FSS NDNAD. That is the fundamental figure that even parliamentary questions will not elucidate.

Odd to think that general press is more open than the forensic press such as FSI,IJLM, JFS,JFSs. The one exception I can think of is International Journal of Legal Medicine (2004 ) 118: p83-89 German DNA Profiling Group , blind trials of testing samples at 136 labs in 31 European countries. Despite using unrealistic 50/50 mixed samples the error-rate expressed in terms of 10loci DNA profiles - 4 percent are erroneous. How many forensic scientists are aware of that one?

No analysis of multi-million arrestee-section databases for false matches which of course is the best way of establishing the true number of false matches between crime-scene profiles and arrestee database. No mention of the database numbers after which false matches are bound to appear just using allele frequency information. 6 loci UK Caucasian approximately 5,000 10 loci UK Caucasian approx 300,000 9 loci Australian Caucasian approx 50,000 9 loci Australian Aborigine approx 25,000 13 loci USA Caucasian approx 2 million

I previously quoted the published number of 6 loci false match numbers (10 in 6,311 + 1 in 573) . If none of those were due to aliases then these above minima may be reduced even further by a factor of 10 or so as it reflects co-ancestry . In other words we have to believe the authorities are quite happy to have multiple criminal records for criminals , so they can choose which previous to be used against them.

Acres of forensic science journal pages happily multiplying numbers together to produce off the planet numbers conveniently ignoring that it only applies if inheritance is independent across different loci, ie no cross-linking of loci/alleles. I was recently reading this weighty tome History and Geography of Human Genes - Cavalli-Sforza et al The Sardinian population comes top in the world in allele frequency terms for inheriting each of these genes MSN*M , HP1 , HLAA*18, HLAA*2 , PGD*A , DIA 2

Remember the newspaper reports concern a match between a crime scene and an arrestee-side database record. Matches contained within such databases or otherwise hidden until there is a repeat of the R v Watters (6 loci) situation of a crime-scene profile matching an existing unrelated database pair , so 3 way match.



The newspapers do not have to report the 'science'. They just report the results as it affects people. Peter Hamkin in 2003 was arrested and forcibly removed to the other side of the country for extradition hearing on charge of murder. He was implicated by DNA database match that was sufficient in UK and Italian administrations to show 'guilt' to be arrested and transported. The Goettingen prisoner would have been arrested because of a false match in the BKA database under the German administration, but inconveniently he was in prison at the time of the murder. John Ruelus in USA would have been charged with rape and murder, unfortunately he was 4 years old at the time.

These are the results of 'scientists' blindly going along as the church did pre Nicholas Copernicus and Galileo Galilei.



Well a false match is one possibility that does not need twisting the facts to fit the case or blaming incompetence/errors in testing. No mention of this possiblity of course. Part Quote http://www.timesdispatch.com/servlet/Satellite? pagename=RTD/MGArticle/RTD_BasicArticle&c=MGArticle&cid=1031781820698 Doubt raised about implicated man

BY FRANK GREEN TIMES-DISPATCH STAFF WRITER Mar 28, 2005 Last year, DNA testing cleared Arthur Lee Whitfield of two 1981 rapes in Norfolk and implicated Aaron Doxie III, an imprisoned sex offender. Now things are not quite so clear. Authorities have turned up evidence raising doubt about the culpability of Doxie, who is serving three life terms for unrelated sexual assaults in 1984. The unusual turn of events pits the sometimes questionable reliability of eyewitnesses against the work of the state crime lab, which is under scrutiny for its work in the case of Earl Washington Jr., who was nearly executed for a rape and murder he did not commit. Not only are the two rape victims in the Whitfield case sticking to their identification of Whitfield, but both said their assailant was not circumcised. The two were assaulted in such a way that they would presumably know. It turns out Doxie is circumcised; Whitfield is not. If the women are not mistaken, it would raise questions about the DNA testing or evidence handling -- or both -- performed by the Virginia Division of Forensic Science. Whitfield was freed on parole in August after the DNA tests. But problems DNA arose for him after he took the formal step of petitioning the Virginia Supreme Court to prove his innocence. <...>

Witch-hunt targets scientists (Australia)

http://www.thecouriermail.news.com.au/common/story_page/0,5936,1264316 7%255E3102,00.html Witch-hunt targets scientists Hedley Thomas 24mar05 SCIENTISTS at the John Tonge Centre are being threatened with jail in the wake of a government hunt for the source of leaks highlighting serious problems in the forensic laboratories.

Queensland Health has ordered a sweeping review of the centre after leaks to The Courier-Mail this month forced an official admission of problems and sparked a review of the centre.

Sources close to the centre said scientific staff were "furious and close to walking out in disgust" after being told to get independent legal advice and prepare for questioning.

Senior bureaucrats will begin a probe into the leaks as early as today.

Scientists have been warned a police investigation is probable and any unauthorised disclosure of information about the troubles at the centre could result in prosecution and imprisonment for two years.

News of the inquiry, which was condoned by Health Minister Gordon Nuttall, was leaked yesterday within minutes of scientists being given formal written notices warning of the ramifications.

"They are upset and feel intimidated," said a source at John Tonge. "They are getting advice on whether they will even turn up. The department wants to include past and present staff in the inquiry."

Scientists met yesterday and took advice from the Queensland Public Sector Union before deciding to flatly refuse to participate in any investigation.

Mr Nuttall's office confirmed the probe, describing it as an "internal audit around the information provided to The Courier- Mail".

Mr Nuttall, who has responded to revelations about equipment and accuracy problems and a huge backlog by ordering an external review and starting the outsourcing of scientific testing, yesterday refused to comment on the crackdown.

In a statement, Queensland Health said: "It is usual practice for Queensland Health's internal Audit Branch to investigate any unauthorised release of confidential documents as such actions are breaches of the Queensland Health Code of Conduct."

Staff, who have been heartened recently that public disclosure of the problems is finally leading to some ministerial action, are furious.

"It has a (management) culture that refuses to accept there's a problem - a culture where everyone who dares to criticise is written off as an idiot," said Ron Grice, a former senior scientist at the centre.

"Staff are demoralised, traumatised and angry. The backlogs there today are worse than three years ago when I left despite the millions of dollars put into the place. Morale is at an all-time low. I often wonder why the whole place doesn't just implode."

Opposition Leader Lawrence Springborg accused the Beattie Government of embarking on a reign of terror "to silence public servants and whistle blowers with legal threats and intimidation".

"Rather than fix the problems and answer the questions, they go out to get even with the people who showed them up," he said. "That's clearly the consequence of raising any concerns about this government - they will get even with you and fit you up."

Mr Beattie, who leaked Crown Law advice about himself last week, told Parliament yesterday that he valued "open, accountable and transparent processes", but it was wrong for public servants to leak material.

The leaks inquiry will try to determine who provided The Courier-Mail with an internal document exposing flaws in the testing of human DNA.

DNA QUESTION

I am not a DNA analyst, nor do I care to be one. LOL Therefore, I am not sure this question will make sense, but here goes: When dealing with a STR or a VNTR are the STR or VNTR on a specific chromosome or are they "fragments" from a number of chromosomes?

Thanks for your help,

These are the 10 STRs used by the UK Forensic Science Service (apparently)

vWA
THO1
D6S502
FGA
D21S11
D18S51
D2S1338
D16S539
D19S433
D3S1358
plus the Amelogenin X /Y notifier
I forget which chromosomes that vWA,THO1 and FGA are variously on but for the remainder the number after the D is the chromosome number. Moot point about what you mean by specific. Notice D6S502 in the above list , that is what they put on their official forms. But unbeknown to themselves, it would seem, what they actually analyse and record is D8S1179 on chromosome 8 and not the D6 one. Would you Adam & Eve it ? Supposedly forensically admissible documentation.

DNA Databasing

Yes, it was routine for long term storage of biological samples to be in a freezer in 1984. That was the year I began training as a crime scene investigator, and the two long term storage options that I recall were drying out the sample or freezing it. I don't know that aren't validation studies of DNA stored for 20 years, they would be simple enough if the contributors of some of the stored DNA were still alive.

There is not even validation study into biological material that has been frozen for 20 years and then tested against current samples from the same contributors. Let alone study of stored material at ambient conditions.

In FSI 112 (2000) page 157 one study into one 17 yearold blood stain stored at ambient which showed the 'heavy' loci D18 and D2 responses so depleted over 17 years as to be almost forensically unuseable. Responses of about 3000 rfu for D19 gradually reducing in peak heights down to D18 and D2 peaks of about 150 rfu . Even that single reported analysis did not have a comparison with a current sample from the same person to check for any changes.

By pure coincidence I saw this report today concerning loss of frozen state for just 4 days. Quote http://www.abqtrib.com/albq/nw_local/article/0,2564,ALBQ_19858_3705941 ,00.html

Freezer error prompts query from victims More than 60 cases are connected to the temporary meltdown in the Police Department's evidence room.

By Joline Gutierrez Krueger Tribune Reporter April 16, 2005

Officials with the District Attorney's Office are attempting to allay crime victims' fears that their cases could be in jeopardy because of a freezer malfunction in the Albuquerque Police Department evidence room.

But whether the victims' cases are among the more than 60 cases District Attorney Kari Brandenburg says are involved in the temporary meltdown two months ago, advocates say the fallout could be emotionally wrenching for victims.

"It's tragic because it not only affects those victims whose cases might directly be connected to the evidence that is destroyed but every victim that has a pending case out there," said Elena Giacci, executive director of the Coalition to Stop Violence Against Native Women. "They start worrying: `Could it be my case? Could my attacker go free?' It brings up the whole trauma again, the emotion that's attached."

Brandenburg says her office has begun to review a list of 1,644 items police said were in the evidence room's faulty freezer to determine what cases were affected.

A list of between 60 and 64 cases was completed Thursday, she said. Of those, most are still pending or have recently been tried or pleaded out, she said.

At least 15 are murder cases, and nine are rape cases, she said.

Sandy Dietz, director of the District Attorney's Office Victim Impact Program, said she and her victim advocates are contacting every victim or family member whose case is on the list.

"People are worried until we begin to explain to them exactly what happened and exactly what is being done," Dietz said.

Prosecutors involved in each case are also speaking with victims and families, she said.

The freezer went down during the weekend of Feb. 19. The problem was discovered Feb. 22, and the freezer repaired Feb. 23, Brandenburg said she learned from a police memo.

A freon leak caused the shutdown, said police Capt. Larry Sonntag, supervisor of the Metropolitan Forensic Science Center. <...> End Quote

All the following is just speculation for consideration. The DNA sections chosen for profiling are in the so-called "junk DNA" areas, where not only are there DNA repeats, but on human evolution time-scale there has been enough mutations to be of use for identity purposes. To me this would suggest that such DNA is not as robust as the "active" DNA. Errors in this DNA , due to stress conditions for example, would not be significant for biological inheritance. But errors in the junk DNA, due to freezing and un-freezing, will not necessarily lead to unviable dogs or humans but could mess up adduced profiles.

Another consideration, harking back to a fundamental assumption. To multiply allele frequencies together, an implicit assumption is made, that all loci/allele inheritance are independent of all others. The "junk DNA" may be involved with (computer parlance) error correction/parity checks cross- coupled to "active" DNA. http://www.nature.com/news/2002/020916/full/020916-4.html by Donall Mac Donaill , subsciption now, or discussed on http://www.idthink.net/biot/error/

Freezing DNA nonarevers

I've checked back to early 90s of indexes/abstracts of FSI & IJLM but nothing found for validation along these lines. Next weekend I will go further back if they are on line.

On freezing All the following is just speculation for consideration. The DNA sections chosen for profiling are in the so-called "junk DNA" areas, where not only are there DNA repeats, but on human evolution time-scale there has been enough mutations to be of use for identity purposes. To me this would suggest that such DNA is not as robust as the "active" DNA. Errors in this DNA , due to stress conditions for example, would not be significant for biological inheritance. But errors in the junk DNA, due to freezing and un-freezing, will not necessarily lead to unviable dogs or humans but could mess up adduced profiles.

My understanding of the law (probably UK and USA) is evidence of this nature can only be submitted in court if validation checks of a scientific procedure have been thouroughly researched and preferably published in peer-review. People have been prosecuted where the sole evidence of any import is DNA profile analysed from cold-case samples - some stored at ambient and some frozen. Also people exonerated using DNA profiles from cold-case samples , equally suspect.

There would seem to be no justification for this, ambient or frozen, and any cases processed in court are then open to be appealed.

Bellow is a link to a recent presentation by my colleague, Margaret Kline, about her experiences with long-term storage of DNA. Several references can be found within the presentation. Margaret has been testing several stains at various conditions (including liquid nitrogen -150 oC... now that's freezing!). Stains stored at room temp will begin to show some degradation over time (no shock there), but typeable DNA was recovered from stains at all samples examined.

As far as potential errors in junk DNA regions due to freeze/thawing, here is my speculation...

Let's suppose that a tube containing 1ng of DNA undergoes several rounds of freeze/thawing. Suppose that the genotype at TH01 in the fresh sample of this individual is 8, 9.3. In 1 ng of DNA, there are approximately 167 total pairs of chromosomes (one cell = 6pg of DNA; 1 ng = 1000pg / 6pg = 166.7 cells). Thus, to believe that freezing and thawing can affect the genotype, on the 167 chromosomes that have an 8 allele at TH01, nearly each and every locus would have to spontaneously have to "mutate" (due to less overall robustness - not sure what that means) to say a 7 allele. Meanwhile... the other 167 chromosomes will "mutate" from a 9.3 allele to... I don't know 9... 10... 11... you get the point. In a sea of 3 billion nucleotide bases only a thimbleful of bases changes occur in the junk regions (I'm not sure of the mechanism here since the cellular enzymes have been inactivated or removed during extraction) of forensically chosen markers to "mess up" genetic profiles.

I think it's easier to believe that DNA can degrade from repeated freeze/thawing by shearing rather than the spontaneous generation of novel alleles.

Here is the link I mentioned earlier...

http://www.cstl.nist.gov/biotech/strbase/pub_pres/KlineMarch2005storag eDNA.pdf

How accurate is forensic science

Hi

I was interested to hear what people think of forensic science and how accurate it is. I have read there have been a few mistakes in the lab but should we rely on as much as we do.

I am reminded of the quote, attributed to John Wanamaker

"I know half the money I spend on advertising is wasted, but I can never find out which half."

Whenever areas of forensic science are subjected to the rigours of blind tests and validation things start coming unstuck. False match statistics for DNA profiles, quoted in courts, are often plain weird unsubstantiated numbers like 640 billion to 1. Subject DNA profiling to multi-lab validation then it emerges that something like only 96 per cent of 10 loci DNA profiles are correct ( even worse for 13 CODIS structure ). See (abstract) http://www.springerlink.com/app/home/contribution.asp? wasp=b82ee8788c4f4b9da0b00953db41ac04&referrer=parent&backto=issue,4,1 3;journal,9,53;linkingpublicationresults,1:101167,1

In normal use no one knows whether a particular DNA profile is in the 96% or the 4% group.

In court presentations of traditional fingerprints even a layman juror, given two non-smudged or skewed enlarged fingerprints, can compare for himself the pattern of termini, bifurcations and enclosures.

Not so with DNA profiles - an abstraction from variations at the molecular level. You cannot give that same juror a microscope so he can see for himself the repeat patterns of C,G,A and Ts. All you can say is that these DNA profiles are self-consistent in that repeating the processing produces the same results.

You cannot state with universal truth that that is the real underlying profile/s.

Is that homozygosity on vWA, D8, FGA,D18 or D5 real or an artifice of the system you are using ?

FSI 143 (2004) 47-52 False Homozygosities comparing 2 DNA profiling kits with samples taken from 2055 individuals showing 15 errors between SGM plus, Powerplex 16 and Profiler systems.

Individual  SGM         Powerplex
vWA
1  	15,15  	15,17
2  	17,17  	17,18
3  	15,15  	15,18
4  	16,16  	16,18
5  	18,18  	18,21
D8S1179
6  	12,12  	12,16
7  	14,14  	10,14
8  	13,13  	13,18
FGA
9  	22,25  	25,25
10  	23,23  	21,23
D18S51
11  	14,16  	14,14
12  	10,10  	10,18
13  	15,16  	15,15
So false homozygosity slippage by as much as 8 alleles.

D5S818 Profiler Powerplex 14 10,11 11,11 15 10,12 12,12

And then of course the more general operational errors highlighted by multi-lab validation International Journal of Legal Medicine (2004 ) 118: p83-89 0.4% of 30,479 single locus validation tests were wrong translating to something like 4 to 5 percent of UK or US profiles.

No way is that truth.

False matches involving unrelated people will not occur in the first instances with people with rare alleles. The first to occur will be people having all 18/ 20 / 26 alleles being greater than 5 per cent allele frequencies. Of all the random simulations of large databases no matches have occured where any of the (AF) allele frequencies are less than 5 per cent. Each of my 20 are greater than 8 per cent compared to ethnic background.

When I start to see court presentations where the minimum AF data is expressed, or similar analytic criterion, then I will know that they are not spouting unsubstantiated Alice in Wonderland twaddle such as
1 in 3 quintillion
1 in 695 quadrillion
1 in 17 quadrillion
1 in 1.82 quadrillion
1 in 25 trillion
I've yet to see a court presentation where consideration is made of whether a defendent could be one of these first tranche of all high AF profiles that can easily be falsey matched in low millions of profiles , long before billions , trillions etc.

Another USA false DNA profile match - updated

Independent confirmation but I have an easy explanation of course. http://www.freep.com/news/metro/leiterman21e_20050621.htm Part Quote UNRAVELING A MYSTERY: Old memories, old killing, new twists June 21, 2005 <...> How a drop of blood found on Mixer's hand that belonged to a then-4- year-old boy will factor into the case is still unclear. The blood belongs to John Ruelas, 40, of Jackson, who was convicted in 2002 of beating his mother to death. DNA evidence from the Ruelas murder was being processed in the Michigan State Police DNA laboratory in Lansing on the same day in 2002 that evidence from the 1969 Mixer case was also being processed. Police have been unable to connect Ruelas to Mixer or Leiterman. The fact that DNA was being processed on the same day raises questions about possible lab contamination. Results of an independent test of the blood, requested by Hiller, shows it belongs to Ruelas, Gabry said. An evidentiary hearing is scheduled for Monday to determine whether an independent analysis of DNA from both Leiterman and Ruelas, requested by Gabry, can be used at trial. Leiterman remains in the Washtenaw County Jail awaiting a July 11 trial.

no mention of using SGM instead of cofiler or whatever, I wonder why

http://www.mlive.com/news/aanews/index.ssf?/base/news- 13/1119967889274150.xml

DNA expert agrees with bizarre results Hearing in 1969 murder case adds to confusion surrounding evidence Tuesday, June 28, 2005 BY ART AISNER News Staff Reporter The testimony during a pretrial hearing did little to clarify the confusing evidence presented so far in the case against Gary Leiterman, charged in the 1969 death of Jane Mixer.

Dan Krane, an associate professor of biological science at Wright State University in Ohio, testified at the

request of Leiterman's defense attorney. Krane said he agreed with the state police lab's findings that DNA

from blood samples on Mixer's body belonged to Mixer, Leiterman and a convicted murderer named John

Ruelas, who would have been 4 years old at the time of Mixer's death.

Leiterman, 62, of Gobles, is charged with murdering Mixer, a 23-year- old law student from Muskegon who

was found shot and strangled in a western Wayne County cemetery in 1969. He was arrested last November

after police matched his DNA obtained after a prescription fraud conviction with DNA found in stains on

Mixer's pantyhose.

His trial is slated to begin July 11.

The pretrial hearing is scheduled to resume next Wednesday with testimony from another expert in DNA

analysis and an official from the crime lab, both called by the prosecution.

The DNA test results came under scrutiny from Washtenaw County Circuit Judge Donald Shelton after a

May hearing when Deputy Chief Assistant County Prosecutor Steven Hiller confirmed Ruelas' DNA was

present in the Mixer sample and that evidence in Leiterman's case was tested on the same day as evidence

from a murder investigation involving Ruelas, 40, of Jackson.

There was no testimony Monday regarding the possibility of contaminated samples at the State Police

laboratory. Hiller declined comment after Monday's hearing but has said he does not believe the evidence

was contaminated.

Defense Attorney Gary Gabry on Tuesday did not say he could prove otherwise, but noted the initial test

results from the lab did not indicate a mixture of DNA samples or the presence of DNA from a minor. He said

he only discovered that information upon Krane's insistence to review all the documentation related to the

tests, including the technician's notes and underlying data.

"I'm troubled by the concerted effort to not make all the information available,'' he said. "If they believe in

their opinion, why not provide all the information that's there?''

End Quote

Ho-hum here we go again

Why do I still keep seeing such reports? http://www.macleans.ca/topstories/news/shownews.jsp?content=n061443A June 14, 2005 - 17:11

Defence expert slams RCMP handling of DNA in 30-year-old murder case

AMY CARMICHAEL

VANCOUVER (CP) - A blood sample used to link murder suspect Robert Bonisteel to the stabbing deaths of two 14-year-old Vancouver girls in 1975 was mishandled by the RCMP, a DNA expert said Tuesday.

The speck of blood found on Bonisteel's shoe, smaller than a dust particle, was kept in unsealed bags that could easily be contaminated, said Dr. Ron Riley. "It's so easy to contaminate a sample with such a small amount of DNA," said Riley, who was testifying for the defence in B.C. Supreme Court.

"It happens in many labs, it's written about all the time. It's a limit of the technology. The sample in this case is just so small I don't think it's scientifically significant. To use it as the foundation of a probable match, I think that's a mistake."

Bonisteel is charged with first-degree murder in the stabbing deaths of Judy Maria Dick and her friend Elizabeth Inge Zeschner.

It took 26 years of testing the sample and considerable advances in DNA science to finally obtain a partial profile suggesting the blood on Bonisteel's shoe belonged to one of the teen victims.

The sample, just six or seven human cells, degraded over time and was too small to be reliable, said Riley.

"They're going below the threshold used by other labs and that's risky. It's such a small amount I don't think it's reliable."

According to lab reports, RCMP scientists placed the fragile matter in uncapped tubes in a spinning centrifuge, right beside samples from the victims. This is done to concentrate the samples, but they should be sealed during the process, Riley said.

Court has also heard the samples were handled by staff who didn't change gloves between touching the victims' bra and sweater and then picking up Bonisteel's shoe.

The Crown accused Riley of having idiosyncratic views not shared by anyone else in the scientific community. Experts for the prosecution have told court the odds of the analysis being wrong are one in 14 billion.

Even with all the alleged mistakes, Riley said the likelihood that the blood on Bonisteel's shoe could belong to someone other than Dick is one in 3.3 billion.

Bonisteel left Vancouver shortly after the bodies of Dick and Zeschner were found in suburban Richmond in February 1975.

His marriage had just broken up and he abandoned his wife and five- week old son. His lawyer James Millar now says Bonisteel was "in a great deal of turmoil" at the time.

On the way to Winnipeg, he raped a woman. Once he reached the city, he raped again. He spent 20 years in jail for the attacks.

Prosecutors allege he killed the 14-year-olds who were so close they said they were sisters.

Police launched a massive undercover operation to try to get a confession.

An investigator posed as the boss of a biker gang in which Bonisteel was desperate to climb the ranks.

The undercover cop told him the police had DNA evidence on him linking him to the murders of Dick and Zeschner. He said Bonisteel had to tell him what happened if he wanted the bike gang to help him make the problem to go away.

Bonisteel's lawyer said his client was afraid of the undercover cop who he believed was a ruthless gang leader.

Millar said Bonisteel just told him what he wanted to hear.

The undercover officer videotaped a long statement by Bonisteel, who described holding a knife in one girl's chest while the other sat terrified in the front seat of his car. He then sliced the other along her rib cage, "because it was the nastiest thing" he could think of. End Quote



Interesting story. I had to read the centrifuge portion twice before I figured out what they were talking about. It sounds as if they were concentrating samples in a speed-vac or with microcon-100's. In the case of the speed vac then yes the samples would all be open at the same time because you can't close them. However, I agree that I would not concentrate suspect and victim samples together. The chances of contamination during this procedure are incredibly remote and I know of no instances of it. Despite this I maintain that I wouldn't do it. It just looks bad even if it really isn't.

As to the experts statement that only " six or seven cells" were in the sample, it sounds a bit unrealistic. That would be approximately 36 to 42 pico grams of DNA. I doubt with extended PCR cycle times and going below threshold you could even obtain a "reliable" partial profile given the age of the sample and the fact the sample has had previous testing, which would decrease the DNA available for current testing. Our labs minimum guide of 200 pico grams, using normal analysis parameters, generally gives a partial profile at best or a weak complete profile.

As to the "contamination" issue. What does sealed mean? A piece of tape on a paper envelope is considered sealed. If that sample spent the entire 20 something years in an unsealed package then they had better have a really good excuse for it or pay the price by a defense reaming. And the glove issue is just simply embarrassing. I never open suspects items while victim items are open. I always change gloves even moving to items from the same individual or even during examination of a single item. We lay our evidence items out on clean butcher paper with new paper for each item. My entire work surface is wiped down with either bleach or RNase between evidence items from different subjects. If I even think for a second I have contaminated my work surface then I will wipe it again prior to opening a new evidence item. Let's just say that I burn through gloves, especially during extraction/clean-up.

I hope that my comments illustrate the point that not all labs are incompetent and we actually do care about what we do. I don't want to wrongly implicate or exclude someone because of sloppy work.

676 quintillion

In the UK, this week, a professor Roy Meadow is being pilloried for criminal abuse of statistics presented in court. Do any forensic statisticians live in the real world ? Multiplying AFs together is just as ridiculous as what Prof Meadow is accused of doing.

http://www.delawareonline.com/apps/pbcs.dll/article? AID=/20050623/NEWS01/506230316/1006 By CHARLOTTE HALE / The News Journal 06/23/2005 <...> But what O'Neill didn't know before a preliminary court hearing Wednesday was how steep the odds are that the DNA belongs to someone else.

Newark police detective Andrew Rubin testified during a preliminary hearing that 18 zeros are needed to create the ratio: one in 676 quintillion. <...>

Self-consistency ?

Who but forensic scientists could make the following reported statements and find a consistent whole ?

"DNA testing of the dried blood last year found it matched another convicted murder, John Ruelas. Ruelas, however, was just 4 years old at the time of the murder and lived in downtown Detroit, a 45-minute drive from the crime scene."

"The lab that handled Mixer's evidence also handled Leiterman's DNA and that of the boy, John D. Ruelas, now 40, who is serving time for the beating death of his mother."

"He also said there will be highly technical testimony on DNA and that experts will tell jurors that the odds of the samples belonging to a Caucasian male other than Leiterman are less than one in 170 trillion. "

"Prosecutors acknowledged that samples in both Leiterman's and Ruelas' cases were tested at the lab on the same day but have denied claims of evidence contamination. "

Sources http://www.courttv.com/trials/leiterman/071305_ctv.html

http://www.freep.com/news/mich/mixer13e_20050713.htm

http://www.mlive.com/news/aanews/index.ssf?/base/news-13/1121263880267860.xml

How dare they present such a dog's breakfast to the court and counter-GIGO fashion expect the court to sort it out. 170 trillion indeed.

So the John Ruelas connection is due to unrelated false match. http://www.mlive.com/news/aanews/index.ssf?/base/news- 13/1121870476251160.xml&coll=2

Wednesday, July 20, 2005

... Leiterman's attorney, Gary Gabry, has maintained that Leiterman never knew Mixer. and that the two were linked only through questionable DNA evidence. What has yet to be explained is the DNA profile of another man, 40-year-old John Ruelas, was in a spot of blood that was found on Mixer along with Leiterman's DNA profile. Ruelas was 4 years old when Mixer died. He is now in prison for killing his mother in Jackson County.

Sylvia Gill, a DNA analyst with the Virginia-based Bode Technology Group, a private forensic lab, testified that her company was asked by the Michigan State Police crime lab to conduct DNA testing. The results, she said, showed Leiterman's DNA samples matched a partial DNA profile on Mixer's stocking.

Megan Shaffer, an assistant director at ReliageneTechnologiesnear New Orleans, another private company that does DNA testing, testified that the test results of a DNA extract of blood off Mixer's left hand were consistent with those of the MSP crime lab. Shaffer said the DNA tests excluded it from being Mixer's own blood.

Previous testimony in the case showed that MSP lab tests found Ruelas' DNA on Mixer's left hand.

From "millions of trillons more times likely" to zero likelihood

No other scientific discipline is allowed to make such nonsense statements without full account of errors. When are forensic 'scientists' going to start telling the truth in courts of law ? . The true probability is far more like 1 in 20 that any 13 loci DNA profile determination is erroneous. That is the only publically available error rate, from all possible sources of error, for forensic labs blind tested (GEDNAP blind trial concept part 2 ,data for year 2002, pub 2004. No single lab from this validation study or any other inter-lab exercise has published their own results, so this pan-Europe reusult is the only one to go by. Until that error rate is up in the trillions to 1 against then such statements are totally bogus and fallacious.

John Ruelas last week and now the latest pile of nonsense reported here http://www.reflector.com/local/content/news/stories/2005/07/26/20050726GDRlincoln.html ... "inherently lacking the scientific foundation and safeguards required in constitutionally protected criminal trials in North Carolina, especially in the absence of strict assurances designed to stop the SBI lab from repeating past mistakes and reporting erroneous results with little integrity and no consequences to the SBI lab or agents responsible." ... "It's pretty shoddy stuff that's coming out of the lab," Savage said. "They're not doing what anybody would do in what I would call a real lab. If you're going to put someone on death row, put someone in jail for life, or even for a year, at least the science needs to be sound."

I would put it a lot stronger than that.



While laboratory error rates are of significance, no one to date has a reliable way of measuring them. Utilizing one study to base lab error on is both foolish and irresponsible. The statisical significance of an STR profile is, in my opnion, not directly related to lab error rate. I believe it is a go/no-go concept. If there is an error then the STR frequency is irrelevant until the error is identified and understood in the context of a case. The best we can do is develop procedures that allow for the detection of error. Also, the procedures should minimize the chance of error.

So a true probability of 1 in 20 is bogus and fallacious. Do you have some math supporting this? I have read several papers on lab error rate and proposed caluclations to modify STR freqeuncies. All the calculations are based on theoretical lab error rates. However, I still maintain that error rate and STR frequencies are mutually exclusive. I believe lab error rates needlessly attempt reduce the statistical significance of a STR profile. Assuming for a moment that one could accurately measure a labs error rate then the following would be fair: The frequency of occurance for a given profile is "A"; however, the chances the lab obtained that result in errror is "B". Good luck with determining "B" though! Not to mention... what is an error? Please define all categories of error that would be used to generate this calculation.

You hammer away at the statistics we use, yet you are willing to take one study and apply it's results in a broad stroke. This seems inconsistent to me. Shouldn't something be well characterized before application?

Delighted to explain. If you are aware of any other inter-lab validation test conducted in blind fashion please tell me. I don't mean internal validation checks as in these terms that is meaningless as using same reagents/machines etc The relevant table of results from the only proper published study I am aware I've placed (fair-use fashion ) on http://www.nutteing2.50megs.com/gednap.gif ( if remote linking to an image does not work it is on a link about 1/2 way down on the URL in sig piece)

It shows 0.4 per cent error rate in 30,479 single locus tests. Combined results from 136 labs in 30 European countries and multi-locus tests across 18 autosomal STRs and 12 Y-STRs. published in International Journal of Legal Medicine (2004 ) 118: p83-89 http://www.springerlink.com/app/home/contribution.asp?wasp=df08a8b230994088a1e8983c28228a00&referrer=parent&backto=issue,4,13;journal,10,54;linkingpublicationresults,1:101167,1 or http://tinyurl.com/cnquy The GEDNAP blind trial concept part 2. This data is anonymised so the good and bad are lumped together - considering the bad do not know they are bad (or at best, in disagreement with the consensus).

Only one error per profile on one locus (1 or both alleles) is sufficient to invalidate a profile. Simple maths 0.4 *13 = 5.2 per cent or 1 in 19 , say 1 in 20 for Codis , 1 in 25 for NDNAD structure

Until more such proper inter-lab validation studies are undertaken and published this is the only series and the only data to work with. We can quibble about 1 locus per profile or 5 per profile or whatever but this report didn't divulge. I can come back by mentioning that the stains were, forensically almost unheard of, 50/50 blood/blood stains. It is still an extremely long way short of 1 in trillions error rate. If practising forensic scientists have not obtained and read this report and others on false homozygosiies etc then shame on them.

All labs say they are error free , because they just don't know otherwise until such blind exercises are undertaken. Then surprise - surprise the bad ones in this GEDNAP process were informed but has anyone seen them mention their individual results - NO.

No links to other relevant inter-lab validation studies heard. So until there is then this Gednap is the best available, don't blame me, I can only use what is available. There was qualitive analysis of the errors discovered but no quantitive breakdown of the "0.4%" figure. Error types Sample transposition Transcription errors Previous studies showed marked errors from certain types of stain so surprise,surprise they settled on the least error prone of fresh blood source only. Wrong interpretation of minor allele and stutter. FGA (42.2) often unrecognised Distinguishing THO 8.3,9,9.3 and 10

They had deliberately used the rare FGA (42.2) but there was no mention of deliberately including homozygous pairs known to produce false homozygous results. Separate study on this showed FSI 143 (2004) 47-52 Same sources processed on SGM plus and Powerplex and compared. 15 errors in 2055 single contributor profiles not otherwise selected to have the following error-prone alleles, so error rate from these otherwise not distinctive or rare loci/allele combinations of 0.7 per cent or 1 in 140
vWA 	  SGM+	  Powerplex16
1 	 15,15 	 15,17
2 	 17,17 	 17,18
3 	 15,15 	 15,18
4 	 16,16 	 16,18
5 	 18,18 	 18,21
D8S1179
6 	 12,12 	 12,16
7 	 14,14 	 10,14
8 	 13,13 	 13,18
FGA
9 	 22,25 	 25,25
10 	 23,23 	 21,23
D18S51
11 	 14,16 	 14,14
12 	 10,10 	 10,18
13 	 15,16 	 15,15
D5S818 comparing Profiler and Powerplex
14 	 10,11 	 11,11
145 	 10,12 	 12,12

Please inform me how many labs cross-check for this source of error by repeating on other systems ? False homozygosity is a systemic failing so I cannot see how error rates can be better than 1 in 140 so sets that bound.

I come from a proper trained scientific background and I keep seeing statements in courts where it is patently obvious that the people speaking have no proper scientific training. Yesterday I saw reference to 3.482 billion and last week reference to 171 trillion. As always there was no mention of the degree of error in these figures. My training says that if a number is given as the result of any processing then if no error bound is given then it is implied by the degree of precision in the stated numbers. The result cannot have a greater degree of precision than the error in the most influential input factor/s. So 3.482 billion is implied to be accurate to the nearest 2 million or even 1 million. 171 trillion is accurate to the nearest trillion, all utter tripe. It is just as grating to the ears of a proper scientist as seeing someone using a calculator and pronouncing that some result is 2.34278547 where even quoting 2.3 would be overstating the precision.

That is before bringing in the matter of the square law of false matches once the threshold has been reached. By the time you got to a billion profiles let alone a trillion there would be millions of unrelated pair matches let alone triples, quadruple matches etc. With no way of predicting whether this defendent's profile would be one of those false matches.

I use Identifiler and our validation and everyday use shows absolutely no evidence of false heterozygosity.

Also, "best available" isn't always the best or even the most useful.





False heterozygosity is not the problem - it is false HOMOzygosity that is the irremoveable 'error' that puts an upper bound on error rates.

I found no reference to Identifier being immune to false homozygosities.

How often do you run a sample both through Identifier and say Powerplex 16 which both analyse the 5 loci shown to be prone to FH. ?

I was trying to be charitable but the best in my terms would have ben the results for Gednap 20 & 21 which show 0.7 per cent error rate or 1 in 11 . After that result they moved the goal posts. They dropped the stains such as "cigarette butts and mixtures of body fluids as well as hairs". Because these samples were producing disproportionately more errors. Beggars belief doesn't it - just what is forensically more likely than 50/50 blood/blood traces. So I'll revise the worst case situation to 1 in 12 profiles being erroneous.

If errors are so rampant how can there be any "known homozygotes" or "known" anythings? All must be tested by lab personnel at one point or another - thereby inciting more error.

How can a known homozygote give false homozygous results? Wouldn't a known homozygote have homozygous results?

AFAIK it is an intractable systemic failing that cannot be overcome by normal single kit analysis. Full explanation of biological reasons are in the full text of which the abstract is http://tinyurl.com/75dbu They undertook further biological research but full textual results/explanations hedged with a lot of "appears"/"appeared to be" Discrepencies on vWA (apparently) due to mutation upstream of the repetitions D8 " " downstream of the repeats FGA " " downstream of repetition D5 " " downstream of repetition D18 mutation Pointers to other published False Homozygosity results for D16 and TPOX

Allelic dropout "due to stochastic effects was also eliminated" The D5 electrophoregram is included and it is not a matter of mis-interpretation. There is not the slightest trace above mush level on Powerplex16 for the '10' trace of D5(10,11) and D5(10,12) shown on Profiler +

As far as I can see this 15 in 2055 or 1 in 140 represents the limit of error for single kit processing, even if absolutely all human error, mis-interprertation etc could be removed. The 2055 subjects in the study were not pre-selected so can be considered generally representative of human populations.

The most simple response to false HOMOzygosity is... SO WHAT?

Missing alleles just means my stats aren't going to be as good. It will never cause me to include someone incorrectly. So I would dispute it as even being a relevant "error". As far as mixtures go, I routinely see allelic dropout in my casework; at least what I perceive as dropout based on camparison to references. Based on your "error" any incomplete profile or mixture profiles are errors. News flash... these are not errors. Incomplete profiles are what they are.

False homozygosity can have some impact on databases in that the presence of an additional allele has to be resolved in the case of a preliminary match. However, we have not encountered this problem at our lab. I am sure it will eventually happen.

When alleles start to "drop-in" then we have a problem. It is known as contamination. The reverse is not true though. So you can't take false homozygosity rates and modify statistics given the fact that they aren't errors. The "missing" allele has already altered the stats.

Excuse my ignorance, but could someone shed some light on 'false homozygosity'?

Is it a missing allele in a profile? If so, would it really be labeled homozygous?

Is it an error that makes a homozygote out of a heterozygote?

False homozygosity is when at a particular loci you only see one allele when in fact there should be two alleles (heterozygosity). It can result from a bad amplification, a mutation in the primer binding site at one allele, or from a mosaic between tissues (I actually know of someone who has this). Regardless, false homozygosity is rare. If it is consistent due to a primer binding site mutation or mosaic condition then the result will be present in any forensic unknown samples and the reference. The analyst will be ignorant of the "error". The chances of a false inclusion due to this phenomenom would be extemely small.

So ,hypothetically, you have an electrophoregram in front of you ,it is a profile from a single individual contributor,clean and uncontaminated and it shows one peak corresponding to vWA 15. No doubt about it just a single peak, perfectly on ladder. This person , unknown to you, tested on another company's system shows two peaks, for vWA (15,17). By what incredible insight do you ascribe vWA (15,17) rather than vWA(15,15) to that single peak on your normal single system/kit analysis?

"we have not encountered this problem at our lab" - have you even looked? , have you tried divided samples on 2 or more systems and actually compared results ?

The "so what" is it puts an unassailable bound on DNA profile accuracy in normal single kit use.

I still have not heard properly constituted rebuttal evidence against the upper and lower bounds for DNA profiles. That is, until proven otherwise, between 1 in 11 and 1 in 140 for CODIS and 1 in 14 to 1 in 140 for FSS/NDNAD.



My reply is that I don't care. It can happen. I can't change it. I would love to see the RFU levels of the profile in which the 17 was absent. The bottom line is that this occurance is rare and as long as the 17 is absent in every sample then it doesn't effect my interpretation of a match.



The FSI 143 (2004) 47-52 report only has plots for the D5 '11,11' and '12,12' Powerplex plots that showed (10,11) and (10,12) on Profile, no RFU levels . Citations in that article give further FH results by other workers so not one isolated study : J. For. Sc. 46 (2001) p637-641 also shows FH of 0.2 per cent for FGA " " " 43 (1998) 1103-1104 shows D16 and TPOX FH http://journalsip.astm.org/JOURNALS/FORENSIC/jofs_toclist.html shows vol/year agreement to these refs but I cannot find the cited articles/abstracts there.

You have not given rebuttal evidence , just a qualative counter assessment. 3 quantitive studies to me, 0 studies to you is not rebuttal. Where is your data for the upper and lower error bounds for single-kit DNA profiles ?



Qualatative is all that is needed and there are no error bounds for the kits that I know of.

As far as I am aware Profiler, Cofiler, Identifiler, GenePrint and PowerPlex are all compliant with the CODIS requirements and results submitted for storage on Codis. These are not mutually consistent as far as false homozygosity (FH) is concerned. It is outrageous that the FH inconsitencies , hence intractable systemic errors, are not determined published and presented in courts.

On the more general theme of errors (human included) I now see that the latest published Gednap report is on the web rather than locked away as expensive subscription access in Int J Leg Med (2004) 111:83-83 http://medweb.uni-muenster.de/institute/remed/spurenkommission/Information/IJLM_GEDNAP_II.pdf

Gednap 24/25 fudged to bring the per locus error rate down from the 0.7 per cent of the earlier Gednap 20 validation trial

http://medweb.uni-muenster.de/institute/remed/spurenkommission/Information/Manual_englisch07_04.pdf ....
GEDNAP 20 the following samples wereprepared:GEDNAP 201. 
Person A: 25Ál blood (female) on cotton cloth2. 
Person B: 25Ál blood (male) on cotton cloth3. 
Person C: 25Ál blood (male) cotton cloth
4. Stain 1: unsmoked filter cigarette with 10Ál saliva
5. Stain 2: 25Ál blood mixture (Persons A:B, mixed 1:2 v/v)
6. Stain 3: 25Ál blood mixture (Persons A:C, mixed 3:1 v/v)
7. Stain 4: Buccal swab from Person A
...
Being the previous criteria, now downgraded to 50/50 blood mixed stains only, no cigarettes etc, to bring the per locus error rate down from 0.7 to 0.4. Despite being a "blind trial" the stains were mixtures of persons A,B and C, known, in these outline terms, to the participants. The full protocols for Gednap 24 to 27 are not available to the public AFAIK (rat smelling time - cf concurrent thread on this group about "ASCLD-LAB accreditation" ).

They were rigorous enough to include THO 9.3 & 10 and FGA 42.2 (perceived as trip-up ones by some ) but if I was running the tests I would make sure a few False Homozygous prone alleles were included eg from pool of the vWA,D8,FGA,D18 or D5 ones mentioned in FSI 134 (2004) 47-52




Email Paul Nutteing by removing 4 of the 5 dots
or email Paul Nutteing ,remove all but one dot
Or a message on usenet group uk.legal has got to me recently a couple of times.
A simulation of a large DNA profile database
A simulation of DNA profile 'families'
A simulation of DNA profile families with consanguinity
A simulation of DNA profile 'families' for 6 generations
dnas.htm revisited with all alleles represented
dnas.htm revisited for >8 percent allele frequency subset (similar ancestry )
Simulation of Taiwanese Tao and Rukai populations to explore the effect of within and without ancestral clusters
Basques autochthonous DNA profiles simulation, 9 loci
Australian Capital Caucasian 9 loci simulation
Australian Capital Caucasian 9 loci simulation, >= 5% allele frequency
CODIS, 13 Loci Caucasian Simulation
Automating the macros
Otner match scenarios
'Peer review' of some of the dnapr.htm material
Continuation of sparring on http://groups.yahoo.com/group/forensic-science/messages with forensic 'scientists' using my pseudonym of Nona Revers or nonarevers
'Peer review' of some of the dnapr.htm material , part3


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