Forensic Genetic Genealogy

December 24, 2019

In a move that a decade ago could have only been imagined by writers of science fiction novels, the Justice Department this month outlined an interim policy for how to use Forensic Genetic Genealogy (FGG) without violating people’s privacy and civil liberties.  FGG (yes- everything in government has to have an acronym) is the practice of connecting DNA from crime sites to relatives using genealogy websites.  The idea is that people who are simply exploring their own personal ancestries may unwittingly help the police solve crimes.

One famous example of this hit close to home for me.  Joseph DeAngelo, also known as the Golden State Killer, lived just 8.9 miles from the Pondera office.  He also is accused of committing at least 13 homicides and 50 rapes across California in the 1970s and 1980s.  DeAngelo retired a few years and neighbors, as usual with people like this, described him as a recluse who would yell at neighbors who approached his fence or who mowed their yards too early in the morning for him.

Police narrowed in on DeAngelo by comparing some DNA evidence from an old crime scene to people who had uploaded their data to a genealogy database called GEDMatch.  They then followed the family tree of a close DNA match and narrowed suspects to people of the right age and geography.  Finally, they took DNA samples from DeAngelo’s trash and by swiping his car door handle while he shopped at a nearby Hobby Lobby.  This game them a direct match to the old crime scene DNA.

While it’s hard to argue with the results of this particular case, privacy advocates can certainly make a case for some pretty scary future scenarios.  It’s good to see that the Justice Department is addressing this topic early and it will be fascinating to see how the FGG technique plays out in the future.