MONTGOMERY COUNTY, Md. (WDVM) — Police say they’ve identified the man they believe is the Potomac River Rapist, who committed crimes in the 1990s. Now we’re learning more about how police narrowed it down to one suspect.

You may have heard of 23andMe, Ancestry DNA, and GEDMatch, they’re all services that are used to tell you more about your family lineage. They’re also being used to solve crimes.

“We began to come up with a strategy to look at this from a genetic genealogy standpoint,” said Chief Marcus Jones.

It’s how police and the FBI identified 60-year-old Giles Daniel Warrick as the suspected Potomac River Rapist. He’s allegedly responsible for at least eight rapes in Montgomery County and one murder in Washington, D.C. Montgomery County Police Chief Marcus Jones explains what lead up to the arrest.

“A team of detectives were able to zero-down on this particular suspect, we were able to obtain a warrant for the suspects DNA,” said Jones.

Police got his DNA after they were able to link him to the crimes through the use of these genealogy databases and finding blood-relatives.

This isn’t the first time detectives have used this technology to identify suspects, investigators used it to identify the Golden State Killer, who was convicted of violent crimes on the West Coast.

“It’s becoming a new trend, that we’re able to solve cold cases,” said Jones.

Warrick will first face trial in Washington, D.C. for the murder charge, and will later be tried for his alleged crimes in Montgomery County.