Scientists and Lawyers Argue For Open US DNA Database

chrb writes "New Scientist has an article questioning the uniqueness of DNA profiles. 41 scientists and lawyers recently published a high-profile Nature article (sub. required) arguing that the FBI should release its complete CODIS database. The request follows research on the already released Arizona state DNA database (a subset of CODIS) which showed a surprisingly large number of matches between the profiles of different individuals, including one between a white man and a black man. The group states that the assumption that a DNA profile represents a unique individual, with only a minuscule probability of a secondary match, has never been independently verified on a large sample of DNA profiles. The new requests follow the FBI's rejection of similar previous requests."

Comments

chimps have 97% of human DNA

[mangu]

Before DNA tests are accepted as conclusive much better studies should be done, particularly for false positives.

I believe DNA tests should be used for finding someone innocent rather than guilty. Negatives aren't that big a problem. If there are discrepancies then obviously it's not the same DNA.

Positives are another issue, how many common features there must be to accept two DNA samples as coming from the same individual?

Re:chimps have 97% of human DNA

[Anonymous Coward]

DNA can be as easily faked as fingerprints. Hell, I could just "accidentially" cut a big politician, while getting his autograph. And then plant that DNA at a murder site. While I myself am completely sealed off in a virus-lab-style overall.
A overall that suffices will be below 50 bucks an a special store. And an autograph just is some travel costs. Everybody can do it.

Why "cut" the politician at all?
Hand them the pen when asking for an autograph, that way you can get skin cells AND a partial fingerprint.

Re:chimps have 97% of human DNA

[TubeSteak]

Before DNA tests are accepted as conclusive much better studies should be done, particularly for false positives.

I agree with you, but I'd add the caveat that the study shouldn't be done with a Federal database that was never intended for the purpose.

Mission creep is the kind of thing /.ers usually rail against, especially when there are privacy implications. If scientists want to study large datasets, they should go put together their own, or buy it from someone who has. What shouldn't be happening is a database meant for law enforcement to be opened up to the public.

Re:chimps have 97% of human DNA

[hedwards]

I disagree, mission creep is serious, but as it stands now there's a sizable database held by the FBI that isn't necessarily known to be totally reliable. Worse is that there isn't really any way of knowing how reliable it is without some sort of outside review. The fact that the FBI has a DNA database should be far more concerning than open access to it. Finger prints were once thought to be unassailable evidence in court, now it turns out that since they typically only require a small portion of the fingerprint to match that it's not really particularly accurate in many cases. Same thing could turn out to be the case here.

Re:chimps have 97% of human DNA

[ceoyoyo]

So basically you're saying you believe witness testimony is more reliable than scientific evidence?

Certainly forensics should be scientifically validated and need to be evaluated in the context off all the evidence, but "paying little attention to forensic details" just because you don't personally understand them in full detail....

How is the testimony of an expert witness, which is scientifically verifiable, any less reliable than the testimony of the defendant, eye witnesses, doctors (expert witnesses themselves), police officers (also expert witnesses), etc?

Re:chimps have 97% of human DNA

[AliasMarlowe]

Before DNA tests are accepted as conclusive much better studies should be done, particularly for false positives.

I agree with you, but I'd add the caveat that the study shouldn't be done with a Federal database that was never intended for the purpose.

You are probably right, if the only conclusion were to be scientific knowledge, so that the database would exist only in the interests of science. Unfortunately, the principal purpose of the FBI database is the provision of strong/irrefutable evidence to secure convictions. Other purposes are to aid in selecting suspects or to eliminate individuals from suspicion. Its suitability for these purposes is what has been questioned, and has never been empirically assessed. Indeed, the cited studies of comparable databases and of a subset of the FBI dataset suggest that the "genetic matches" are not irrefutable, and may be considerably weaker evidence than presented in court.
The FBI database should be quantitatively assessed for suitability for its intended purpose.

Re:chimps have 97% of human DNA

[FuckingNickName]

Unlike DNA evidence,

You are the juror, not the forensic scientist. You are not being presented with the opportunity to collect and test DNA yourself. Even if you were to ignore the evidence that separate people can appear to have matching DNA as tested, and the evidence that evidence is often planted, and evidence that accidental contamination occurs, you are still assuming that the forensic scientist is accurately reporting his results, i.e. is both competent and impartial.

there have been many, many studies proving the unreliability of eyewitnesses. In a stressful, quick situation, people's memory is often wrong.

This is precisely why you don't rely on a single eyewitness, nor even on a group of eyewitnesses alone to make your case.

So because you're a doofus who didn't pay attention in school, you ignore the facts?

I don't know about AC, but I have had enough years of schooling to have a good idea of what I do not know, and one of the things I do not know is forensic science. All I can do is judge the reliability of the expert witness's interpretation, just as I do for all the other witnesses. I have also had enough schooling to know that, the more complex a system, the more difficult it is to identify any tampering which has occurred.

Re:chimps have 97% of human DNA

[Vellmont]

The jury is not there as an expert in forensic science

The jury is also not an expert in eyewitness testimony. You accuse those who believe in forensic and expert testimony of making an appeal to authority. I accuse you of making an appeal to the infallibility of individuals and memory. People lie, have bad memories, are influenced by what they heard elsewhere, and insulate themselves from anything contradicting what they think they saw. How is that not as equally inaccurate as forensic evidence or expert testimony?

You don't have to pay a lot of attention to realize this. Just read any news story the day after it happened, and then later on find out what actually occurred. One example that sticks out of my mind was when the DC sniper was running amok, eyewitnesses claimed that the shots came from a white van. Later of course we all learned that John Muhammad was driving a blue Chevy Caprice (which you may note looks nothing like a white van). It doesn't take a lot of effort to find wild inaccuracies in eye-witness accounts.

You're right that we shouldn't take forensic evidence as a gold standard above all else. It simply needs to be interpreted with the unreliability of ALL evidence.

Re:chimps have 97% of human DNA

[FuckingNickName]

I agree with this, with the additional proviso that (as I indicated below) it's more difficult to identify tampering of a complex system, especially one you're not very familiar with.

We're all fairly familiar with the acts of recalling and forgetting events we've seen, and we will (as good jurors) expect multiple independent eyewitness accounts if we are going to rely on eyewitness testimony. But we're not very familiar with the intricacies of collecting and testing DNA, and (as successes of convictions on DNA evidence show) it doesn't seem that we're putting on our critical thinking hats on when presented with complex science[tm] by authority.

Re:chimps have 97% of human DNA

[noidentity]

He didn't say he took witness testimony at face value; he said he looks at inconsistencies, etc. And his suspicion of evidence requiring an expect to interpret wasn't because he couldn't understand it per se, it was because he couldn't fully trust those who claimed to understand it, and couldn't fully trust that it wasn't planted. In other words, he values things he can directly perceive over those he must take at face value.

Re:What exactly

[hedwards]

If they were given to clear their name, then the DNA shouldn't appear in the database at all. The knowledge from the DNA database is hardly something that you're average stalker is going to have much use for, the people that you don't want to have access are probably the FBI.

Privacy concerns?

[Vellmont]

Having the names of the people associated with each DNA analysis would be completely unnecessary. Just assign each person a unique, meaningless number in place of their name and the problem is solved. There's probably 6 other ways to solve the privacy problem and still make the data useful. If researchers find special cases where they need actual identities to better understand what's going on, make them sign NDAs and release the information to only them.

The FBI doesn't want to release this because they know there's a lot of partial or complete matches in the database. Suddenly having news stories about how there's 100 people in the FBI DNA database with the same 13 identifiers (flash to expert testimony claiming billions to one of such a match) would be a major disaster for the FBI. The FBI would then talk about how most of them are the same person using different names, and various other explanations, but the damage would be done (flash to news story about one side of a match being a 22 year old male from Alaska, and another a 76 year old female from Florida).

I understand why the FBI doesn't want to do this, but it's extremely important data about how valid this type of DNA testing is (especially within certain populations) (flash to news story about racism). Essentially the government holds evidence about the validity of DNA testing that's relevant to thousands of criminal cases that it refuses to release. That sounds like a strong constitutional issue to me.

Re:Anonymized?

[Ironsides]

No, it wouldn't, for two reasons given in the article. First is that it is possible someone has two entries in the database. The only way to discover this is to find a matching pair of DNA sequences and then look at the personally identifiable information to figure out if you have a duplicate or not. Second, is the possibility the information in the database was entered wrong, and that someones profile does not match what their DNA is.

p = (1/4)^(#base pairs)?

[multi io]

Forgive me that I'm a layperson who didn't RTFA, but this story makes me wonder how they actually arrive at these astronomically low probabilities that the DNA profiles of two different people are accidentally identical? They wouldn't just include some random base pairs in the profiles and then calculate the probability as p=(1/4)^(number of base pairs), which would not account for the fact that 99.xxx percent of all base pairs are identical in all humans... would they? I was always assuming that, given that scientists who know what they're doing should have invented this test, there was some sophisticated process that would ensure that they would somehow only choose base pairs from the subset that was actually different in different individuals (and, more specifically, where each of A,C,G and T would have a 0.25 probability of occuring). I'm still relatively confident that something like this takes place, but sometimes you can be just astonished at how stupid people can be...

Re:Misuse Of Statistics

[Jane Q. Public]

As another poster stated, however, there are other factors that can skew even those odds.

For example, depending on the circumstances surrounding the crime, the probability of someone having planted the DNA evidence is often much greater than a billion to one, or even millions to one.

High probabilities are one thing, but grossly distorted "statistics" in the courtroom do not serve justice.

Re:Misuse Of Statistics

[Anonymous Coward]

The thing is, that 1,000,000:1 statistic is an *average* -- the standard deviation is quite large. There are some clusters where you could match over 1,000 other people on a DNA test, and some people might be the only match in the UK. The kicker is that unless the sequence being matched is very well known, they're unlikely to know which group the presented match falls into.

Re:Misuse Of Statistics

[honkycat]

If only that were the case. For example, from page 2 of http://articles.latimes.com/2008/jul/20/local/me-dna20:

In a typical criminal case, investigators look for matches to a specific profile. But the Arizona search looked for any matches among all the thousands of profiles in the database, greatly increasing the odds of finding them.

[emphasis added] What you say is how it usually works, and how it stands any chance of being statistically valid. In some cases I've read about (not sure if it's in the story I linked to or not), the raw "1 in 100 billion" type odds were presented, which is plainly and patently false when used in this manner, and I believe the defense was not allowed to correct this. Some states do not allow this sort of search, per the article, but some do.

However, this is not relevant to independent checking of statistics. I'm sure the FBI has done at least some good faith testing of their methods, but they are also far too interested in the outcomes of those tests to be trusted with that without some verification.

Re:How data would be misused

[brian_tanner]

I don't understand what is to fall for. I guess it depends on if you are doing multiple comparisons or a single test.

If you independently identified a suspect and could put together a case against them, and *then* got a DNA match, slam dunk. In that case you're right, the jury should not fall for that argument.

However, what about the situation where DNA is found at a crime scene, and then a database search yields a match? Perhaps that person has no alibi or way to explain how what is apparently their DNA got into this rape victim. Then the defense should surely ask "How many people would have to be in the database before a DNA sample from the crime scene will match somebody?" If those odds are not infinitesimal and the case is built around DNA evidence, there is a big problem.

Re:Two measures?

[ChrisMaple]

There's this misconception that people lose their civil rights by becoming criminals. They don't.

A properly convicted criminal serving a jail sentence has lost a portion of his rights, the most obvious being the right to leave the jail.

Rights are what you have as a result of being human, i.e. a rational animal. When you act to hurt an innocent person (violating his rights), you have thrown away some portion of your rights immediately. If the violated rights are among those recognized by the government and you're caught and successfully prosecuted, then the government can punish or force restitution in proportion to the damaged rights of the hurt person. The government does this without violating your rights because you have forfeited them to the extent of the damage you've done. When the punishment or restitution is complete, the deficit in your rights is gone. Your rights are restored - whether the government recognizes it or not.

Rights in the sense of civil rights or political rights have a lot of similarity to the phrase "It is right that." If you are about to leave a grocery with a can of soup, "it is right that" you pay the grocer: he has a right to be paid.

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The protection of others is not the only reason governments jail people (and please don't confuse government with the fiction that is society). Punishment, political revenge, "protective custody", "crimes" that have no victims, are all reasons government use for imprisonment.