A man accused of sexually assaulting 10 women, killing one of them, in Washington and Maryland in the 1990s, was arrested, 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 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 Christine Mirzayan, 29, 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 have linked DNA evidence, police said.
The two D.C. attacks occurred within 2 miles of each other about two years apart. The first victim in D.C., a 58-year-old woman, was sexually assaulted in July 1996, police said.
Mirzayan, who worked as a policy fellow in D.C. and lived at Georgetown University in August 1998, was raped and fatally beaten with a rock. She had recently gotten 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." The first assault was in May 1991. The last known Maryland assault occurred in November 1997.
The string of assaults spanned across the large D.C. suburb and dipped down into the District. As the attacks continued over the years, they got "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 crime scenes with family members who had their data publicly online. Police reached out to family members to try to 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 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.
Warrick lived in the D.C. metropolitan area for years and 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."
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This article originally appeared on USA TODAY: 'Potomac River Rapist': Suspect arrested with DNA