Family Tree Forensics


In 2018, law enforcement using the assistance of GEDMatch a DNA database made up of millions of volunteered DNA samples managed to use that database and the work of a DNA sleuth to capture Serial Rapist Joseph DeAngelo. At that time (The Golden State Killer), it was predicted that family tree forensics would be used even more by law enforcement. GEDMatch officially changed its terms of service to let users of the site know that GEDMatch would be available to law enforcement bureaus.

And it has solved at least 5 more cold case murders in Pennsylvania, Washington, Texas, Michigan, and Virginia, as well as helping identify a man who committed suicide at a Seattle motel just a few days after the attacks on the World Trade Center towers who checked in under a false name.

In the Washington murder case, two Canadians came down to run errands in the Sea-Tac area and were found murdered on a deserted road. The man had been strangled, the girl raped and shot in the head. The man they arrested wasn’t in the system, his DNA didn’t appear in any of the local or national forensics databases. Any crimes he committed after the murders were not crimes where DNA could be forcibly taken and put into the national forensic databases.

The case was 30+ years old with no new leads. He wouldn’t have been caught if two of his cousins had not provided samples to GEDMatch. I’m all for putting murderers in prison, but I would be horrified if the power I gave to the SCTU was wielded by any branch of law enforcement. And I’m not convinced that law enforcement having access to GEDMatch isn’t a little close to the powers outlined by the SCTU. I could actually go back and forth on this thought process for days. Sometimes, I’m okay with, sometimes I’m not and I do believe in taking responsibility for one’s own actions – if you don’t want to go to prison for murder, don’t commit murder – but should your cousins’ attempts to find out their ancestry be used against you – but again…

However, I can think of lots of exciting ways to use it. How about the Orange Socks case? Not the killer’s DNA, but hers, could it help us find out who she was and return her to her people? Or what about the family found in barrels in New Hampshire?

I mentioned a DNA sleuth earlier, it is a necessary part of Family Tree Forensics, someone who understands DNA has to work back from the available samples in the database to get to a person. Sometimes, the DNA in the database are cousins to the sample. That requires someone to fill in the blanks, how can Person X (the unknown sample) be related to Person A and Person B? For instance, one of the cases had an complication because the person they thought should have provided paternal DNA didn’t… in other words, he wasn’t the child of his father apparently. Which created a hitch.

Furthermore, sometimes “cousins” don’t share as much DNA as one would think. I know the DNA I share with my first cousins on my mom’s side is much closer in relation to each other than the DNA I share with my first cousins on my dad’s side because of divorces, re-marriages, etc.

As this continues to grow, I’ll try to keep up on it, I think it is fascinating and could be so helpful for crime fighting and identification of John and Jane Does. (I would love to see DNA work done in the Talmud Shud case, both phenotyping and family tree could be incredibly exciting).

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