The South Carolina man accused of being the “Potomac River Rapist” appeared in a D.C. courtroom for the first time on Thursday.

Giles Warrick, 60, has been charged with the 1998 rape and murder of Christine Mirzayan, a 29-year-old intern at the National Academy of Sciences, in Georgetown.

Warrick has also been linked to rapes in Montgomery County, Maryland. See a map of those attacks here.

Arrested last week, the Conway, South Carolina, man did not fight extradition to D.C. During Thursday’s hearing, he was clad in a gray hoodie and sweatpants, and spoke softly.

Authorities credited the arrest to genetic genealogy, which allowed comparing the attacker’s DNA with what was available on public databases. A similar arrest happened in the “Golden State Killer” case.

Warrick is being held without bond. Another hearing is scheduled for January.

WTOP’s Megan Cloherty contributed to this report.