Investigators using DNA from genealogy websites to catch criminals

In a FOX 32 special report: the power of your DNA.

Last month, the accused “Golden State Killer” was tracked down thanks to his relative's DNA from a genealogy website.

So we wanted to know, could you be turning on your relatives by finding out about your past?

It's a case so cold-blooded that police kept up their investigation for more than 40 years. The so-called “Golden State Killer” is accused of killing at least 12 people and raping dozens of women. The big break came just weeks ago from a genealogy website.

Here's what happened. Police matched a DNA sample from the crime scene to DNA on a site called GED Match. Then, detectives went to work, following the suspect and taking DNA he left behind in public to see if it all matched up. It did, and now Joseph James Deangelo is behind bars.

“This ancestry, and the genealogy, it's an investigative tool,” said Ashely Hall.

Hall is an assistant professor in the Forensics Science Program at UIC. She says genealogy is a new tool that investigators are starting to use to solve crimes. 

“When these things are on the genealogy websites, it becomes advantageous. Because they are publicly available,” she said.

It's easy to argue that using one of these sites to catch a serial killer is a good thing. But could you be putting yourself or your relatives at risk for police investigations if you use these sites? We went to some of the more popular sites and asked.

Both “23 and Me” and “Ancestry” say they won't share your data with law enforcement unless they're legally required. Ancestry says it advocates for its members’ privacy, while 23 and Me adds it has never given customer information to law enforcement.

“I think police will attempt to use it, because it is a powerful tool,” Hall said.

Chicago police tell us they've never used a genealogy site to solve a case, but “it's hard to say about the future.”

Hall maintains that having access to these databases is just one piece of the crime-solving puzzle, and it's up to detectives to do the rest. 

“That's what these are, they're investigative leads, they're not the end of the case,” Hall said.