How Family Tree DNA Caught The Golden State Killer


In 2018, the world became acquainted with Family Tree DNA. It actually wasn’t new technology in 2018. It’s been around for a while. It’s just been very quietly used right up until it caught a prolific rapist and serial killer James D’Angelo aka The Golden State Killer.

The system is actually very controversial with privacy advocates arguing there is nothing more private than a person’s DNA. Here’s what happened in that case. It is complicated, just FYI. So I’ll try to make it less complicated to understand.

Between 1974 and 1986, police had a prolific rapist on their hands known as the East Side Rapist. They had a less prolific serial killer, The Original Night Stalker (yep, before Richard Ramirez earned the moniker, someone else had it). There was also a prolific burglar in southern California that may have been connected to either the East Side Rapist or the Original Night Stalker. Police weren’t sure.

There were literally hundreds of suspects in the three cases and the cases crossed multiple jurisdictions, which made it even messier. In 2001, DNA from cold cases were logged into the California crime DNA database. And the East Side Rapist case was genetically linked to the Original Night Stalker and some of the burglary cases. A task force was formed and the cases reopened and the killer renamed to The Golden State Killer.

He had bled at a couple of the burglaries. He had left seminal fluid at several of the rapes and the murder scenes. In 2005, serial killer BTK (real name Dennis Rader) plead guilty because he could not explain away the familial DNA match BTK had to Rader’s children. He’d basically been caught red handed. A motion to suppress the familial DNA evidence was ruled against in the pre-trial motions. After BTK basically sent the police a business card with his name and address on it, and police obtained DNA samples from both of Rader’s children to compare to DNA left by BTK. Rader was obviously the father of Rader’s children and Rader couldn’t build a defense around it.

In 2007, a handful of states, including Colorado, decided that law enforcement could use public DNA databases to search for suspects in cold cases that involved violent crime with a warrant. The argument goes like this, “the perpetrator of the crime, voluntarily leaves DNA at the crime scene, if it is a large enough sample to be tested, then it should be allowable for that sample to be checked against open DNA databases, because the databases are made up of people who volunteered their DNA reports” (you send your DNA to 23&Me or any of the other companies that do it, and they send you a report about your heritage, you can then submit that DNA report to companies like GEDMatch and search for genetic relatives to get a more complete look at your genealogy.

Between 2007 and 2018 there were a handful of cold cases solved using these public DNA databases. But nothing that earned the public DNA databases notoriety or lots of headlines in the news.

In 2016, law enforcement in California went to GEDMatch with the DNA profile of the Golden State Killer. There were no familial matches. However, at the time, 23&Me, Ancestry.com, and several others were growing in popularity as people searched for the genetic lineage. As a result databases such as GEDMatch were also growing in popularity. In 2017, the DNA of the Golden State Killer was submitted again to GEDMatch. At the time, law enforcement was conducting the search of GEDMatch with a warrant, meaning even if GEDMatch hadn’t wanted to cooperate, they would have been compelled to do it anyway.

In 2017, a familial match for the Golden State Killer was found. A genetic genealogist was able to compare that volunteered report to the report of the Golden State Killer and discovered they were 2nd cousins (if I remember correctly). Police began to investigate James D’Angelo who had once worked in law enforcement as a viable suspect in the Golden State Killer case.

Police actually followed D’Angelo around and watched him throw away a piece of trash (possibly a disposable cup) that they removed from the trash and compared his DNA to that of the Golden State Killer and it was a perfect match.

In 2018, the State of California charged James D’Angelo with multiple counts of murder and suddenly Family Tree DNA was mainstream news. As was GEDMatch, the database company that law enforcement had searched to find the familial link. In May 2018, GEDMatch changed its privacy policy, announcing to all users that the database was an investigative tool that could be searched by law enforcement officers without the need for a warrant. And the ethics debate began, was it actually ethical to let law enforcement have unrestricted access to a DNA database like GEDMatch and the specialists GEDMatch employs, because the genetic genealogists kept on staff by GEDMatch are part of the law enforcement package, not only can law enforcement submit samples and receive information back without need of a warrant, but the genetic genealogists that work for GEDMatch assist law enforcement with the sample submission and do the leg work involved in discovering familial links.

I mentioned Colorado earlier for a specific reason. Nearly every case that has involved Family Tree DNA has involved violent crimes, essentially murders. In 2009, Colorado submitted a sample to an open DNA database of a car burglar. There was some property damage and I think the amount of stuff stolen was only about a hundred dollars (not even a felony). A match was found and the burglar was arrested and charged with the crime.

I bring it up because this work is time consuming. It’s not just about finding a match with a similar DNA profile. The heritage of each sample has to be traced and a family tree somewhat mapped out, which is easier to do when you have a name than when you don’t. Tracking genealogical records to see if the two samples are indeed related and who the unknown sample might belong to within the family tree that has been mapped. Now, nearly all genealogists today work with genetic evidence to prove kinship. It still takes a lot of man hours to track down the genealogy of a genetic sample, let alone two genetic samples one without any information other than what can be gleaned from the DNA report (white male, brown eyes, blond hair, mainly of Eastern European heritage – haplogroups are amazing). Should something this time consuming be used for car burglary, especially a car burglary that is only a felony because windows are expensive?

Don’t get me wrong, all criminals should be punished for their crimes. I just believe that this investigative technique is so involved and time consuming that it should be used for violent crimes. Having your car burglarized sucks, but no one died, so perhaps the means weren’t justified by the end in that case.

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