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FBI Fights Testing For False DNA Matches 411

Statesman writes "The Los Angeles Times reports that an Arizona crime lab technician found two felons with remarkably similar genetic profiles, so similar that they would ordinarily be accepted in court as a match, but one felon was black and the other white. The FBI estimated the odds of unrelated people sharing those genetic markers to be as remote as 1 in 113 billion. Dozens of similar matches have been found, and these findings raise questions about the accuracy of the FBI's DNA statistics. Scientists and legal experts want to test the accuracy of official statistics using the nearly 6 million profiles in CODIS, the national system that includes most state and local databases. The FBI has tried to block distribution of the Arizona results and is blocking people from performing similar searches using CODIS. A legal fight is brewing over whether the nation's genetic databases ought to be opened to wider scrutiny. At stake is the credibility of the odds often cited in DNA cases, which can suggest an all but certain link between a suspect and a crime scene."
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FBI Fights Testing For False DNA Matches

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  • well, well... (Score:5, Interesting)

    by fyngyrz ( 762201 ) * on Saturday July 19, 2008 @11:06PM (#24258851) Homepage Journal

    What we're seeing here is a crack in the government's facade of fake-goodness. The ideas we're fed are that justice is blind, which means (we're taught), ultimately fair; that prosecutors and judges and the legal system in general have our best interests at heart, and so on, platitude after platitude...

    But the truth peers 'round the corner here. They're not interested in accuracy, else they'd be all for determining how well this works, or not. The process and the results would both be open. What they're interested in are convictions, because that's how they keep score. That's how the public is keeping score.

    This is unfair and irresponsible on two fronts. First, if you get the wrong person for any reason (including using DNA evidence that is supposed to be basically infallible, but is, in fact, fallible); then you've done a wrong to that person, of course. But secondly, for every false conviction the prosecutor and their accomplices notch into their pistols, the real criminal is now completely free -- the case is closed. They're not even looking.

    As a society, we need to stop trying to raise up any part of the system based upon count of arrests, convictions, tickets, etc. The temptation to go for easy answers is too high; obviously, if the FBI itself is victim to this, an organization that prides itself on its organizational integrity, groups that have less tradition of trying to do right -- like the local cops who broke down your neighbors door last week -- are going to fall even more prey to such pressures.

    As we see that the FBI tries to prevent the truth from coming out about a tool that is less effective than they claim, as they try to prevent exonerating information from reaching the defense, we see true colors.

    These people are not our defenders; they claim to be, but they have their own agenda, and it is not about fairness. They're simply counting scalps.

  • by Anonymous Coward on Saturday July 19, 2008 @11:16PM (#24258915)

    Please support radical transparency [wikipedia.org] and open source the government [wikipedia.org].

    If everything is out in the open, there can be no hiding.

  • by Anonymous Coward on Saturday July 19, 2008 @11:17PM (#24258917)

    This story is total scientifically illiterate bullshit. A 9-locus match between unrelated people is not surprising. That's why we don't sue only 9 loci, idiots! There has never yet been a 13-locus match seen between unrelated people in the national database- despite the 5 million or so profiles currently in it. I'm sure the average Slashdot reader can manage to work out how many pairwise comparisons that is. (Hint- it's a pretty fucking big number.)

  • by jmauro ( 32523 ) on Saturday July 19, 2008 @11:21PM (#24258961)

    if that's true why bother suppressing it and just let the do the comparisons. It'd be easy enough to bury them in regular scientific testing since the database would show that the hypothesis of these researchers is blatantly wrong and the only time being wasted is their time and not the FBI's.

  • by Anonymous Coward on Saturday July 19, 2008 @11:25PM (#24258985)

    No, it's not wrong. There are over 5 million profiles in the national database. Any slashdot reader should be able to work out how many pairwise comparisons are made when a database that size is searched against itself, and what the expected number of hits is when the match probability is about 1 in 100 billion.

    This story is old news, and simply illustrates why we use 13 loci (average match probability around 1 in a quadrillion or less) and not 9. There has not been a 13-locus match between unrelated people in the database, confirming that the match probability estimates are indeed conservative as they're designed to be.

  • Re:well, well... (Score:4, Interesting)

    by kesuki ( 321456 ) on Saturday July 19, 2008 @11:25PM (#24258987) Journal

    what is really shocking here, is that these 'matches' were being found in arizona, which has less than 2% of the Us population, unless a lot of other places outsource DNA testing to arizona it suggests that DNA fingerprints are little better than regular fingerprints.

    TFA isn't very clear, except that she was working for the state of arizona when she noticed 'identical' matches.

    some might suggest that some of the DNA used to identify criminals may have impacts on that persons likelihood to turn to crime.. but we really don't understand much of how the brain works or the effects of slight variations in dna on that.

  • Makes sense (Score:3, Interesting)

    by Joking611 ( 1321913 ) on Saturday July 19, 2008 @11:26PM (#24258999) Homepage
    Why would they (law enforcement) not want there to be some doubt to DNA results? They're also being used to overturn old convictions. In the case of current investigations, there is also other information (fingerprints, etc.) to help match a suspect to a crime...
  • very worrysome (Score:5, Interesting)

    by Anonymous Coward on Saturday July 19, 2008 @11:40PM (#24259083)

    As an American once arrested by the SS/FBI for computer related crime a while ago, DNA testing always worried me. I can understand it for violent offenders (which is how it was started and then carried over to all felons).

    I can also tell you, if you refuse to submit to testing, they give you what they call "diesel therapy," taking you away from the cushy club fed camp you were in and busing you around the system until you relent. If you were given a half way house sentence or probation, they can revoke either for not submitting a sample.

    Dispite turning my life around, finishing my degree and now working as a developer for a medium-size firm, I worry at times that one night I'll be hauled away because some flunky at the FBI mixed up DNA samples or didn't compare them correctly. I can imagine this being a horror scenario for anyone who's never broken the law, but can anyone imagine there being even a slight chance a bunch of narrow minded, non-technical cops are going to believe me, even if the crime is something totally unrelated to my history?

  • Re:well, well... (Score:4, Interesting)

    by DaedalusHKX ( 660194 ) on Saturday July 19, 2008 @11:42PM (#24259103) Journal

    Anyone with skill and with a true criminal mindset (as in, REAL criminals with an axe to grind) will be able to fool the feds. As far as I understand, they're no different than the KGB... they have to present a list of victims... AHEM... "apprehended criminals" in order to justify their existence.

    Nothing new. They'll keep criminalizing innocent, harmless things and letting real criminals go. The prison industry is bigger than Chinese outsourcing, but you won't hear about it on CNN or even on the alternative news sites. Nobody wants to mention that outsourcing to China is no different in any aspect than outsourcing government furniture (just an example) to prison labor, which undercuts even the Chinese commies on price. Why do you think they are letting out violent felons while taking in white collar boys for shit crimes nobody cares about? Exactly... a violent felon is a liability to a budding industrial power (aka... the new forced labor camps called "corrections facilities"). A meek and easily subdued white collar boy, well he's easy to walk all over and he's afraid of his fellow inmates AND the guards. He'll do as he's told. Why risk angry violent felons incarcerated with the very profitable and nonviolent white collar "criminals" ?

    Bingo. You've said it well chief, but missed the "profit" motive, which is what existed under communism, it existed under socialism, under fascism and in this fascist/socialist hybrid system that we have here in America. Nothing new... just different masks on the same old faces.

  • by raehl ( 609729 ) <(moc.oohay) (ta) (113lhear)> on Saturday July 19, 2008 @11:47PM (#24259129) Homepage

    What we're seeing is a consequence of basic math.

    1/113 billion chance a particular person has the same DNA profile as me. 6 million records. So I have a 6 million / 113 billion chance of matching someone else in the database. Drop some zeros and thats 6/113,000. Of course, each of the 6 million people in the database has a the same chance of matching someone - so that's 6/113,000*6,000,000 - which means there should be 318 people who match someone else in CODIS, or 159 'matches'.

    # of people matching = size of group * size of group * chance of match

    Anytime you have something that has a small chance of matching, but a fairly large sampling group, your chances of matching are high, because your chances of a match existing within the group is the SQUARE of the group size.

    So it would be surprising if there were NOT people who matched in CODIS. The question is, are there more or less that 318 of them, and how much more or less?

  • Re:well, well... (Score:5, Interesting)

    by khayman80 ( 824400 ) on Sunday July 20, 2008 @12:16AM (#24259311) Homepage Journal
    Unless they were looking for a serial killer, who tend to be white males.
  • by Jerf ( 17166 ) on Sunday July 20, 2008 @12:27AM (#24259393) Journal

    It's probably even worse than the naive math indicates, because odds are not everybody involved will actually be unrelated in the mathematical sense anymore.

    On the other hand... as others point out, in the birthday paradox there's a huge difference between two people have the same birthday and someone has the same birthday as me. However, in a prosecution situation, it is the latter that matters, not the former. Simply showing that the birthday paradox applies doesn't really prove that for a given criminal, that the odds are high that the match is a false positive.

    This is also why government attempts (by well meaning people) to simple run dragnets over large datasets looking for "bad people" need to be resisted; while the birthday paradox is not always in play, similar statistical effects can be found in many other situations that cause enormous amounts of false positives. "Due process", where we investigate someone with all available tools only after we already have good reason to suspect them (to simplify, of course), turns out to be important not just for our rights in the abstract, but statistically sound, as well.

    At the risk of potentially defending the government (pause for the shocked intake of breath), I find it quite plausible that the government knows all of this, and is resisting this investigation because they do not look forward to explaining this to every jury unto the end of time. While I support open disclosure and letting the chips fall where they may as a matter of principle, if you take a moment to look at this from their point of view, even if you dare take the step of assuming they're not actually out to get you personally (pause for another shocked breath), you might find it hard to avoid having a little sympathy for their position. (If you're still having a hard time, engage the "Most jury members sure are dumb, ha-ha!" cynicism circuit and consider the implications.)

  • by kaos07 ( 1113443 ) on Sunday July 20, 2008 @12:42AM (#24259479)

    I think the really cool thing about this whole story is what it says about "race". For hundreds, if not thousands of years, and even now, people have using "race" and skin colour as reasons for subjugation. But here we have the first cast of extremely close matching DNA, 1 in 113 billion, and they are from different "races". Wow.

    This, if anything, should dispel any stupid theories about the difference of "race" within the human species.

  • by Ichijo ( 607641 ) on Sunday July 20, 2008 @12:45AM (#24259493) Journal

    I match 12 out of 12 Y-DNA markers with 9 other people who have had their DNA tested. Based on our last names, none of us are related.

    I don't think you should be able to use blind searches of a DNA database as evidence, because it's too easy to get false positives. It's only useful evidence against someone you've already found by other means, or as a way to generate leads.

  • by Anonymous Coward on Sunday July 20, 2008 @12:55AM (#24259539)

    "We have to refocus everyone on the Rights of the Innocent"

    No, we need to focus on rights and fairness, period. Cops aren't always truthful. Drug dealers sometimes don't lie.

    Renaming basic human rights and due process, i.e. Rights of the Innocent, to some special "needs" category plays into special interest. Much like how "victim rights" laws throw to the wind fair court cases; the defense has their name thrown in multitude of papers and intense scrutiny, while the victim hides in anonymity. This has resulted in inequities in handling of cases--this become hugely apparant in both the Duke rape case and the Kobe Bryant rape case; consider these were big name cases where the flaws were apparant and utilized by the prosecution. (If you're wondering what should happen--if the victim's name is protectd in a case, the defense's name should also be protected in the case.)

    Furthermore, such new terminology often is at some point redefined and abused--most of the citizens of the United States still don't realize that "violent" offenses constitute mere drug use or sex (so called statutory rape) under the 1984 Bail Reform Act (this is why California's 3 strikes laws ends up taking in so many repeat offenders). I can easily see "rights of the innocent" laws being ineffective and creating a special class as one-time DUI offenders now accused of murder get denied a "special class" of rights.

    The facts are rather simple--for the past 60 years, laws have gone overly pro-prosecution. Part of this is government keepign score, as someone else put it. Part of this is also on the general public for being stupid, scared, and greedy--why people will look less horrified at a murderer than a pet killer, or if they see someone shackled they presume guilt, or see some sick social advantage in another person being locked up (prison doors open as the economy tanks means more jobs for the "innocent" sort of thinking).

  • Re:well, well... (Score:5, Interesting)

    by D'Sphitz ( 699604 ) on Sunday July 20, 2008 @01:32AM (#24259689) Journal
    I agree 100%. We see all the time stories about new evidence in death row cases. The first thing the prosecutor always argues is "he doesn't deserve a new trial, I stand by the conviction". If they truly cared about justice they'd say "hey we need to take another look at this". I don't know how they can live with that on their conscience anymore than I understand how defense lawyers can live with setting rapists and killers free on technicalities. I think the answer is that most lawyers in general lack a conscience, you'd have to to be successful.

    I have seen first hand how the justice system truly works. Back in my youth I was a bit of a delinquent, and was convicted of many fairly petty crimes, mostly misdemeanor but nothing worse than a gross misdemeanor. I freely admit that I was usually guilty as charged, and I took my licks, but there were two cases where I was absolutely innocent.

    Part of their strategy is to charge you with everything in the book, that way when plea bargaining comes around they can act like they are doing you a favor by dropping the extraneous charges if you plead to the main charge. The prosecutor had absolutely no interest in justice and wasn't interested in explanations or evidence, it was made very clear that if I refused to plead guilty it was going to cost me. In retrospect i'm confident I would have won both cases had I gone to trial, but the scare tactics can be quite effective, especially on a 20 year old kid.

    I accepted the plea bargain in both cases to stay out of jail and avoid a costly trial and missing more work. Being innocent is just as costly as being guilty. Ironically I had to tell the judge under oath that I was really guilty and wasn't just saying so for the sake of the plea bargain. The convictions went on my permanent record and I got some hefty fines and probation, and the prosecutor got 2 more notches on her holster. 8 years later these convictions in particular, which were gross misdemeanors, cost me a very nice job.

    Like I said, it was fairly petty and doesn't compare with the innocent people who are rotting in prison right now, but I can definitely sympathize. We see it all the time, people pleading guilty to avoid the death penalty or long prison sentences. When it is more of a punishment to prove your innocence than it is to plead guilty, something is wrong with the system.
  • by tgv ( 254536 ) on Sunday July 20, 2008 @01:54AM (#24259795) Journal

    One addition: if you multiply 0.00005309 by 6,000,000, you get 318, which is the number of duplicate matches you can expect in the 6 million database. So, it's not really surprising that the Arizona lab did find a (near) match. Still, the chances of a false match for an individual are 0.00005309, so the question about its effectiveness/usefulness is: how many profiles are compared against the database per year?

  • by dgatwood ( 11270 ) on Sunday July 20, 2008 @02:01AM (#24259817) Homepage Journal

    If they can sufficiently suppress this story, they will have a lot less jurors quoting the news byte as absolute proof that DNA evidence can't be trusted.

    And of course DNA can't be trusted without other corroborating evidence. If they find my hair in the car of somebody who turns up dead (or vice-versa) there's many orders of magnitude greater chance that one of us gave the other a ride than that one of us killed the other (unless I'm dead, in which case, fry her, please. KIDDING!)

    The harsh reality is that even if you ignore/solve the issue of family members sharing genetic markers and other flaws in common testing procedures, DNA is still just as circumstantial as pretty much any other non-eyewitness/videotape evidence of the crime. What's scary is how many people hear about a sample of DNA being found at the scene of the crime and automatically jump to a conclusion of guilt because they saw on Law & Order (or insert any other similar show here) that DNA was a way to reliably identify the criminal, and then are slack-jawed in disbelief when it is revealed that the person had an airtight alibi (e.g. he/she was in another country at the time of the crime). That's both entertaining and terrifying all at the same time.

  • Practical truths... (Score:5, Interesting)

    by fahrbot-bot ( 874524 ) on Sunday July 20, 2008 @02:34AM (#24259921)
    Not to troll, but law enforcement agencies are really more interested in convictions than the truth. For instance, Virginia has a law that places a 21-day time limit on new evidence that can be used to exonerate someone wrongly convicted. I'm sure the FBI doesn't want it's coveted CODIS database subject to any doubt.
  • Comment removed (Score:3, Interesting)

    by account_deleted ( 4530225 ) on Sunday July 20, 2008 @03:48AM (#24260193)
    Comment removed based on user account deletion
  • by eric76 ( 679787 ) on Sunday July 20, 2008 @05:08AM (#24260505)

    it illustrates the issue nicely.

    Well, maybe not.

    From the article, the real issue appears to be that they make the assumption that the markers are independent of each other without having done the research.

    In fact, they should know better than that. From DNA as a forensic instrument [columbia.edu]:

    THE ISSUES SURROUNDING genetic information in trials may soon become more complicated. The next likely controversy will concern the science of population genetics. Even if a combination of markers is rare among all people, it might appear at higher rates in some ethnic subgroups, says Conrad Gilliam, professor of genetics and development at Columbia. He testified in the 1990 case Castro v. New York State, the first in which a prosecution's attempted use of DNA data was thrown out by the court.

    Suppose a murder is committed in Chinatown, Gilliam conjectures, and the police find blood samples. Certain polymorphic variants that occur frequently in Chinese people are rare in Caucasians. If these markers show up in the sample, and the police produce a Chinese suspect, a prosecutor could try to use the DNA as further evidence against him. "However," Gilliam says, "a defense attorney could argue that there could be so many local suspects with the same profile that the evidence has no bearing on the case."

    If the markers were truly independent, the polymorphic variants mentioned would be random as well.

    So if the above is true, the markers aren't independent and they know it.

  • by Hektor_Troy ( 262592 ) on Sunday July 20, 2008 @08:12AM (#24261215)

    Since you know a lot more about statistics than I do, this might be a question better answered by you than anyone I know:

    Since chimps and humans share about 97% of our DNA, does that mean that if the "odds" of matching with a human is 1:113,000,000,000 that the "odds" of it matching with a chimp is 1:116,500,000,000?

  • Re:well, well... (Score:5, Interesting)

    by Archtech ( 159117 ) on Sunday July 20, 2008 @08:22AM (#24261271)

    Yes, but regular fingerprints are actually very good. That's why it's called "DNA fingerprints" and not "DNA shoeprints" or "DNA ballistics evidence".

    Brandon Mayfield might disagree. Had he not been able to prove beyond a shadow of doubt (as in hundreds of eyewitnesses) that he was in Portland, Oregon when the FBI said he was killing people in Spain, he would have been in a peck of trouble.

    Note the closing sentence of the following story: "an FBI fingerprint examiner told an expert hired by Mayfield the original print no longer exists".

    Fancy that.

    http://www.policeone.com/investigations/articles/88280-Newspaper-Faults-FBI-Examiner-in-Madrid-Bombing-Fingerprint-Case/ [policeone.com]

    Note that it doesn't really matter whether the actual fingerprints were a perfect match or not. What matters is that the FBI lab said they were.

  • by Hektor_Troy ( 262592 ) on Sunday July 20, 2008 @08:22AM (#24261273)

    CSI type shows are partly to blame

    Very true. When's the last time you saw any kind of cop show, where they admitted to have screwed up? I can only remember it being done in Numb3ers in two episodes. One and a half actually, because only one of the shows talked about the fingerprints being misidentifed and the wrong guy being thrown in jail. The other was just a wrong assumption on their parts resulting in a manhunt.

    Hell, I'd love for a show like 24 to have Jack Bauer or whomever torture the wrong guy for hours on end only to finally realise "woops - wrong guy. Guess the stuff he admitted to was just to get out of more beatings"

  • Re:well, well... (Score:2, Interesting)

    by iminplaya ( 723125 ) on Sunday July 20, 2008 @10:07AM (#24261893) Journal

    While your post may be better stated than mine, it is pretty much what I am saying about targeting. The law was designed this way for a reason. Alcohol prohibition cast too wide a net, got too many good ol' boys. In fact you could put the blame for marijuana prohibition squarely on William Randolph Hearst as a pretext to drive out the Mexicans. Though some will blame the Mormon Church. Now of course, it is used like many laws to give the police "probable cause". And "containment" is very profitable for the pirates who run the system. The numbers make it quite clear what this is about. Our own failure to resist does our country, and the world a great disservice. "It is convenient to have a system where everyone is a criminal" - Godwin...er, uh, well, you know who...

    "Marihuana influences Negroes to look at white people in the eye, step on white men's shadows and look at a white woman twice."

    "When some beet field peon takes a few traces of this stuff... he thinks he has just been elected president of Mexico, so he starts out to execute all his political enemies."

    "All Mexicans are crazy, and this stuff [marijuana] is what makes them crazy."

    "There are 100,000 total marijuana smokers in the US, and most are Negroes, Hispanics, Filipinos, and entertainers. Their Satanic music, jazz, and swing, result from marijuana use. This marijuana causes white women to seek sexual relations with Negroes, entertainers, and any others."

    "...the primary reason to outlaw marijuana is its effect on the degenerate races."

    "Reefer makes darkies think they're as good as white men."

    "Marihuana leads to pacifism and communist brainwashing"

  • by Odder ( 1288958 ) on Sunday July 20, 2008 @10:56AM (#24262323)

    Unchecked state power is a danger to everyone. The FBI's court filings to prevent DNA statistical studies are transparently self serving. Imagine if they got their wish and had everyone in their database [stallman.org]. Million of innocent people would be subjected to unreasonable suspicions. Such plans should be abandoned and all efforts made to release people who were wrongly convicted, something that DNA testing seems to be good for. Great injustice has been done because the state granted itself the power to punish based on what it considered reasonable extrapolation instead of truth backed up by real data. It reminds me of witch trials.

    Prison violence proves that surrendering your rights to the state does not make you safe. All kinds of state wards have suffered all kinds of abuse in direct proportion to the control and trust guardians are given. It is nearly impossible to administer justice in a place where no one is trusted but abuse must always be checked for and discouraged. This is one of the reasons state supported torture is so horrible. A cruel state that is more interested in punishment and revenge than it is in justice and protection will abuse guilty and innocent people alike. The ultimate abuse, however, remains the loss of life.

  • Re:well, well... (Score:3, Interesting)

    by sjames ( 1099 ) on Sunday July 20, 2008 @09:26PM (#24267963) Homepage Journal

    Alas, there were 122 matches on 9 loci found in a database of 65000 records (1 in 500) in a single state. There were 20 matches on 10 loci. The matches at 11 and 12 were eliminated because the pairs turned out to be related.

    Note that 9 loci are considered "adequate" by "experts".

    The figures suggest that if everyone was in the database, we could expect 7500 matches on a search restricted to a decent sized metro area.

    I agree that DNA evidence should be considered exclusionary. At most, it could suggest suspects but even then, without more, it shouldn't be considered probable cause.

  • by blitziod ( 591194 ) on Sunday July 20, 2008 @10:52PM (#24268711)
    one of the key witnesses for the OJ trial, I forget his name, had said that DNA was a great tool for excluding suspects BUT not good enough to ID them. He was a noble prize winner for his work inventing PCR dna tech. Of course everyone dismissed him at the time as a hired gun for OJ, I guess he gets the last laugh today!

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