Re:New federal rules limit police searches of family tree DN...
by jessaustin on Thursday September 26, 2019 @11:01PM
(#21088029)
The hypothesis of this example is that the unfortunate suspect's DNA "matches" the crime scene DNA. Of course it's going to "match" when they test it again. The point is that when the original match is against a huge population, you're going to find a bunch of matches, most or all of whom are innocent. Picking one out of that set and then confirming that one is really in that set doesn't prove anything.
Re:New federal rules limit police searches of family tree DN...
by bloak on Friday September 27, 2019 @02:49AM
(#21089146)
I'm not an expert, but I would guess it would be possible to have an exact match on the genetic fingerprinting, but then do a full genome sequencing to confirm that the two samples are from different people.
The funny thing is that although I have often heard about the police finding an exact DNA match with someone who was provably not at the crime scene, I've never heard about anyone doing a different DNA test afterwards to investigate what happened: did a fragment of skin get carried in the wind from one city to another, did samples get mixed up in a laboratory, or was the match a false one, akin to a hash collision?
These genetic databases are tools used for investigation to identify suspects. Once the suspect is identified, the investigators still have to build a case against them, including obtaining their DNA directly for testing against the crime scene DNA. Since all the cases I've read about the police got the suspect's DNA samples from the garbage, it doesn't seem like the genetic research itself is even enough to get a warrant for the suspect's DNA.