An alleged serial rapist who assaulted 10 women, killing one of them, in Washington, D.C., and Maryland in the 1990s was arrested, solving a decades-old cold case, authorities said Thursday.

Giles Daniel Warrick, 60, was arrested in Conway, South Carolina, on multiple rape charges and a murder charge in D.C. and Maryland.

The arrest came through the use of DNA evidence collected from crime scenes and recently connected to Warrick through forensic genealogy, authorities said. Police in D.C. and Montgomery County, Maryland, and the FBI led the investigation

Warrick, in custody in South Carolina, will be extradited to D.C., Metro police chief Peter Newsham said at a news conference Thursday.

From 1991 to 1998, the Potomac River Rapist “brazenly and brutally preyed upon women in the Washington area,” the FBI said in a 2011 plea for information on the assailant. 

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Two of the rapes, including the murder of 29-year-old Christine Mirzayan, the assailant’s last known victim, occurred in D.C. Eight others occurred in Montgomery County. Warrick faces charges for both D.C. cases but only six Maryland cases with linked DNA evidence, police said.

The two D.C. attacks occurred within two miles of each other but about two years apart. The first victim in D.C., a 58-year-old woman, was sexually assaulted on Saturday night in July 1996, police say.

Mirzayan, who was working as a policy fellow in D.C. and living at Georgetown University in August 1998, was raped and fatally beaten with a rock, police say. She had recently married after earning a Ph.D. in California.

“I can’t begin to imagine what these families have suffered over these 29 years,” Newsham said at a news conference Thursday. 

In Montgomery County, police said the man would “cut the phone lines, force entry into homes, cover the victims’ heads and sexually assault them.” Warrick allegedly first assaulted a women there in May 1991. His last known Maryland assault occurred in November 1997.

His alleged string of assaults spanned across the large D.C. suburb and dipped down into the District. As the attacks continued over the years, they appeared to get “progressively more violent,” Newsham said.

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Montgomery County Police Chief Marcus Jones said a detective used genealogy companies, which allow people to track down their ancestry and family, to build out a family tree in the case.

Authorities connected the DNA from the crime scene with family members who had their data publicly online. Police then reached out to family members to see if they could find a suspect who had lived in the D.C. area in the 1990s, which led them to Warrick.

“This is a tool. It’s public information that’s out. I know there’s a lot of debate about it now, but the reality is that it is proven that we are now able to give victims … a little bit of justice, you might say, a closure,” Jones said.

The case follows many recent cold-case arrests nationwide that employ genealogical data to track down suspects.

Jones said it’s possible there are additional victims in the area unknown by police to be connected to the case.

Warrick had been living in the D.C. metropolitan area for years and only recently moved to South Carolina, Jones said. At the time of the attacks, Warrick worked as a landscaper and a contractor for a utility company.

“We’re hoping this will bring some closure to the families,” Newsham said, describing the arrest as “bittersweet.”

Follow USA TODAY’s Ryan Miller on Twitter @RyanW_Miller