Investigators who found Golden State Killer through DNA website borrowed idea from another case
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The idea of using a DNA website to catch a serial murderer began with a search for the identity of an abandoned 5-year-old girl named Lisa.
That sleuthing led police to a suspected serial killer believed to have killed Lisa’s mother, giving a California investigator the idea of using the same technique to find the Golden State Killer, the New York Times reports. The story partly relies on details from the Boston Globe and Forensic Magazine.
Lisa’s identity was unclear when she was abandoned in 1986 at a California trailer park by a drifter who claimed to be her father. The man was later arrested in connection with a murder in California, and died in prison in 2010.
Lisa submitted DNA to three websites, and when matches to second and third cousins were found, two of the relatives agreed to upload their DNA profiles to GEDMatch, which allows comparisons of information from the databases of multiple companies.
Investigators helping Lisa discovered she was a girl from Manchester, New Hampshire, whose mother had disappeared. The town was near Bear Brook State Park, where the bodies of a woman and three young girls were discovered buried in metal drums. Using a DNA sample from the drifter, police found that the body in one of the drums was his biological daughter.
And the drifter who abandoned Lisa was not her father, DNA showed. He was a man who used so many aliases that investigators didn’t know his true identity. With the help of similar DNA techniques, police eventually identified the drifter as Terry Peder Rasmussen.
Police say Rasmussen was originally from Colorado, and they believe he is responsible for several murders across the country.
An investigator in the Golden State Killer case, Paul Holes of the Contra Costa County District Attorney’s office, was briefed on the New Hampshire investigation because he had worked on the California murder case that put Rasmussen in prison.
“I’m listening and I’m thinking, how can I use this technique in my other big case?” he said in an interview with the Times. “And that’s when I went on a deep dive with this technology.”
Holes submitted DNA from a Golden State Killer crime scene to GEDmatch to find relatives and ancestors of the suspect. The DNA led police to the suspect, 72-year-old former police officer Joseph James DeAngelo.
