The Sacramento Bee reported the police pursuit of the murderer/rapist who terrorized California about forty years ago came to an end thanks to information-sharing databases where people from all over the world help one another locate distant family and build a family tree.
Former policeman Joseph James DeAngelo, known as the Golden State Killer, is suspected of committing at least 12 murders, more than 50 rapes, and over 100 burglaries in California from 1976 through 1986. He committed crimes throughout the state and in different regions before it was conclusively known that all were committed by the same person.
Investigators decided to take advantage of the fact that in recent years there is a growing number of sites offering users to share genetic material to track relatives all over the world. Federal investigators created a GEDmatch username to pose as a citizen seeking to find his extended family.
After setting up the fictional user, they fed DNA collected at the murder scenes and asked the site and the rest of its community to help those with similar genetic makeup so the user could get to know his family.
It soon became clear that the "user's" DNA profile was very similar to a number of the suspect's distant relatives. This marked the first breakthrough. After finding this group of relatives, investigators continued to the more advanced stage in consultation with experts and realized that the suspect was actually a DeAngelo.
The entire process took four months, during which there was an erroneous identification and almost one false arrest. The sophisticated method has led to criticism that law enforcement authorities used fraudulent methods by creating a fake profile on the site and pretending to be a person seeking to build his family tree. Authorities made it clear they did not violate any norm or law, but used tools available to ordinary citizens.
The Sacramento Bee reports that although DeAngelo spent several days in custody, investigators still don't appear to have a clear picture of who he is.
They know he was a police officer from 1973 to 1976 and from 1976 to 1979, and they know he worked as a truck mechanic from 1989 to 2017.
They also know he is separated from his wife and has three adult daughters, one of whom lived with him along with DeAngelo's granddaughter. The other two daughters "are very bright, beautiful, and successful," investigator Paul Holes said. One is a doctor and the other a PhD candidate. They had no clue about their father's alleged criminal past; in fact, Holes said they didn't even know he was a police officer.
"For all three of these kids, another tragedy is to find out that their dad is the worst serial killer maybe in the nation's history," Holes said.