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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."
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?
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.
AccountKiller
The FBI's database only uses 15 markers, checking 15 sites in DNA. That's not good enough, and there are false matches. The problem is that they're using DNA technology from about 1990.
23andme, the commercial DNA analysis service, checks 580,000 sites in DNA. 23andme probably has enough data to validate the quality of the FBI's marker selection. That's a good way to check. Identical twins do match, even at the 23andme level of analysis.
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.