(Yes, as long as the system remains honest, and nobody does any switcheroos with evidence. imo.)Excellent point Deugirtni! It works both ways.
Not the same thing, but it seems that things have already been in the works to limit LE's use of genealogical databases. This USA article is from a year ago.
The U.S. Department of Justice (DOJ) released new rules yesterday governing when police can use genetic genealogy to track down suspects in serious crimes—the first-ever policy covering how these databases, popular among amateur genealogists, should be used in law enforcement attempts to balance public safety and privacy concerns.
The value of these websites for law enforcement was highlighted last year when Joseph DeAngelo was charged with a series of rapes and murders that had occurred decades earlier. Investigators tracked down the suspect, dubbed the Golden State Killer, by uploading a DNA profile from a crime scene to a public ancestry website, identifying distant relatives, then using traditional genealogy and other information to narrow their search. The approach has led to arrests in at least 60 cold cases around the country.
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Under the new policy, police can’t quietly upload a fake profile to a genealogy website, as some have done in hopes of finding a suspect’s distant relatives, without first identifying themselves. And the site itself must have informed its users that law enforcement agencies may search their data.
The policy also bars police from using a suspect’s DNA profile to look for genes related to disease risks or psychological traits. Another provision attempts to limit situations in which police secretly take a DNA sample from a suspect’s relative—from a discarded cup or tissue, for example—to help home in on a suspect. The policy says the person must give their informed consent unless police have obtained a search warrant.
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The growing use of genetic genealogy searches—McGuire says she’s heard of 300 active cases using the approach—hit a roadblock in May when GEDmatch, a free database used in most of the cases cracked so far, revised its policy to allow such searches only for customers who had agreed to be included. That “opt in” policy has reduced by 90%, from 1.4 million to 140,000, the number of profiles police can search, according to a recent news report, making it much less useful.
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New federal rules limit police searches of family tree DNA databases