Can police legally obtain your DNA from 23andMe, Ancestry?

Last week, the Food and Drug Administration authorized personal genomics company 23andMe to sell genetic tests that could tell consumers about their risks of developing 10 different diseases, including Alzheimer’s and Parkinson’s. (Photo by William Thomas Cain/Getty Images)

The DNA you send in the mail through genetics kits and ancestry programs like 23andMe and Ancestry can be used by police in a criminal investigation, but it doesn't happen very often.

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Recently, Joseph James DeAngelo, the man authorities suspect is the so-called Golden State Killer responsible for at least a dozen murders and 50 rapes in the 1970s and 80s, was arrested more than three decades after the last killing.

And according to the Sacramento County district attorney's office, investigators used information from an online genealogical site to determine whether the DNA from one of the crime scenes was a match, the Associated Press reported.

» RELATED: Do popular DNA tests like 23andMe, Ancestry actually work?

California police plan to use a similar process  via a private lab to track down the identity of the infamous Zodiac Killer who murdered at least five people and injured two others in the late 1960s.

But both Ancestry.com and 23andMe, two of the largest companies that produce genetic profiles for customers who provide DNA samples, said they don't work with law enforcement unless they receive a court order. Neither companies received a court order regarding the DeAngelo case.

Ancestry.com told AP it hasn't received such requests for genetic information in the last three years. A 23andMe spokesman added that the company "has never given customer information to law enforcement officials" and that it doesn't allow third party access to their genetic data. for comparison.

More than 1.2 million customers have sent their saliva to 23andMe to learn about their own genetics, though not everyone is aware that police can potentially have access to their DNA.

"We try to make information available on the website in various forms, so through Frequently Asked Questions, through information in our privacy center," 23andMe privacy officer Kate Black told Action News Jax last year.

Police have only requested information from 23andMe for five Americans and according to 23andMe reports, the company didn’t turn over any information.

"In each of these cases, 23andMe successfully resisted the request and protected our customers' data from release to law enforcement," Black and colleague Zerina Curevac wrote in a 2016 blog post.

But Black said she wouldn’t rule out the possibility in the future and seeks to review requests on “a case-by-case basis.”

In the 23andMe blog post, Black and Curevac address multiple privacy concerns and questions involving law enforcement and their DNA.

They wrote that typically police will collect the DNA of an unknown suspect at a crime scene and compare it to the federal government’s genetic information database, the Combined DNA Index System or “CODIS.”

Using CODIS, police can run a search to see if the DNA matches that of a convicted offender or arrestee profile in the database. They can also run a “familial search” to identify close biological relatives.

If no matches are found, police may turn to privately owned databases.

But 23andMe and other ancestry tools aren’t likely to be useful to law enforcement or to the government, Black and Curevac wrote.

Their genetic tests can’t be used to match CODIS information or information in other governmental databases because the genotyping technology is very different.

And, even if police are presented a situation in which their testing would be useful, they would still face tough legal and technical limitations.

These limitations are usually enough to persuade police to back off their requests, according to the blog.

23andMe posts law enforcement requests on its public Transparency Report.

While police have been unable to obtain DNA information from 23andMe, in 2014, Ancestry self-reported that it released a customer’s DNA sample to police in compliance with a search warrant.

According to Ancestry's website, the company "requires valid legal process in order to produce information about our users. We comply with legitimate requests in accordance with applicable law."

The investigation involved the 1996 murder and rape of 18-year-old Angie Dodge in Idaho Falls, Idaho, Mashable reported. Police believed there was another suspect involved in addition to Christopher Tapp, who was sentenced to life in prison in 1998.

The 2014 Ancestry results found a close (but not exact) match, which police believed to be Tapp’s relative.

After showing up at donor Michael Usry Jr.'s doorstep in New Orleans, Louisiana, for a six-hour interrogation and blood drawing, police determined it wasn't a match, Mashable reported.

Ancestry's Transparency Report states that the company received nine valid law enforcement requests in 2016 and provided information on eight of the requests  to government agencies. All were related to credit card misuse and identity theft.

The Associated Press contributed to this story.