Science, Now + Beyond

The saliva you sent to trace your lineage might get a relative arrested

What the Golden State Killer case means for genealogy testing sites

Chances are that the vile of saliva you sent to find your distant relatives are being used for more than tracing family lineage, it’s probably helping solve cold cases.

Earlier in the year, police arrested Joseph James DeAngelo, a former police officer linked to a list of murders and rapes in California dating from the early 1970s to the late 80s. He would be known by many names: the East Side Rapist, the Visalia Ransacker, the Original Night Stalker, the Golden State Killer. The arrest was prompted after DNA collected from an old crime scene got a pingback when police submitted it to a genealogy website called GEDmatch where they found distant relatives matching his genetic profile, Paul Holes, the lead investigator, and retired Contra Costa County District Attorney inspector told the Mercury News

According to Holes, the match came from distant relatives to which his team drafted more than 25 different family trees. The tree that eventually linked to the Golden State Killer was so large, it contained more than 100 people, he said.

We like to believe that our genetic makeup is distinctly our own, but we are similar to our neighbors than we like to think. According to 23 and Me, the variables that separate us from one other and make more unique is what genealogy companies use to find your lineage. When you submit your DNA to these genealogy sites, they are deciphering the genetic material you inherited from both parents. This can be anything from a history of lung disease to physical and character traits, which are best and easily identify through one’s saliva. From there, the lab techs search and match these variants like your tendency to crack your knuckles when stressed with other samples in their database that fit the same MO. The results can let you see who and what you are, as well as, offer the opportunity to find previously unknown relatives.

When it comes to familial DNA in criminal cases, the process is similar but instead of cross-referencing the DNA sample with other salvia donators itching to know their lineage, the run the saliva with the DNA found at the crime scene or taken during booking.

GEDmatch, which lists that between 900,000 and a million users, was instrumental to DeAngelo’s arrest since it allows individuals to upload and share their information for free, compared to companies like 23andMe and Ancestry. This feature makes the information accessible to researchers, private citizens, but particularly law enforcement.

Tracing the ‘Golden State Killer’ through genealogy isn’t an isolated case. A month after DeAngelo was arrested, Washington State police announced that William Earl Talbott II was charged for the double murder of Tanya Van Cuylenborg, 18, and Jay Cook, 21in 1987. The police had matched his DNA using GEDmatch as well, thanks in part to of Parabon NanoLabs, the forensics company that did the analysis.

Said company would go on to upload DNA data from about 100 crime scenes into GEDmatch, according to a Buzzfeed interview with the company. Twenty of the cases submitted, the company says,  found matches with people estimated to be the suspect’s third cousins or even closer relatives.

“We were actually pretty surprised,” Ellen Greytak, Parabon’s director of bioinformatics, told BuzzFeed News. With those known genetic connections, she said, investigators have a good chance of using genealogical research to draw family trees and identify possible suspects. Some arrests could come quickly, she suggested. “I think there is going to be press around this very soon.”

While genealogy testing and familial DNA has helped investigators arrest suspects, like in the case of the ‘Grim Sleeper’ where 57-year-old Lonnie David Franklin Jr., was arrested for the killings of 10 young black women and one man beginning in 1985, the process raises red flags in critics who are concerned with genetic privacy.

Privacy advocates fear that genealogy sites that give access to law enforcement aren’t protecting consumer’s genetic information and are held to the same standards as physicians or health insurance companies. The 2008 Genetic Information and Non-Discrimination Act prohibits insurance companies from using genetic information to make eligibility, coverage or premium-setting decisions. It even goes on to prevent employers from including genetic data in their decisions about hiring, firing, and promotions.

However, most of the commercial genetic testing companies that have been contacted by police investigators to cooperate in the past have not followed through with the request,  STAT reports.

A representative for 23andMe, probably the biggest player in the space, tells TIME that “Broadly speaking, it’s our policy to resist all law enforcement inquiries to protect customer privacy. 23andMe has never given customer information to law enforcement officials.”

Even still, genealogy sites like 23andMe do warn customers that “Under certain circumstances, your information may be subject to disclosure pursuant to a judicial or other government subpoenas, warrant or order, or in coordination with regulatory authorities,” on the company’s website.