DNA testing confirms 'serial killer' in Washington County, Pennsylvania, in 1970s: State police

Police say the suspect died in 2023.

WASHINGTON COUNTY, Pa. -- State police in Pennsylvania announced DNA testing has tied together two long-standing cold case deaths and allegedly confirmed a "serial killer" was in Washington County in southwestern Pennsylvania in the 1970s.

Authorities alleged at a press conference on Wednesday that James Richard Clark Sr., who was born in 1957 and died at 66 in 2023, was responsible for the murders of both Susan Rush and Brenda Ritter.

He was 19 and 20 years old, respectively, at the time of the two homicides, and lived in the Washington County area at the time, state police said.

"Testing confirmed there was a serial killer in Washington County during this time frame," said Cpl. James Petrosky, the criminal investigation assessment supervisor with Troop B of the Pennsylvania State Police at the press conference.

According to ABC News Pittsburgh WTAE, authorities said Rush was found dead, sexually assaulted and strangled in the trunk of her car in 1976.

Ritter, 18, was killed in 1977. Her remains were found on a hillside, and authorities determined she had been sexually assaulted and strangled, according to WTAE.

Petrosky said additional DNA testing was done in May of 2025, and "identified the same offender murdered both Susan Rush and Brenda Ritter," Petrosky said.

Authorities said families of both victims have been notified and have asked for privacy.

Taking questions at the press conference, Petrosky said authorities were not ruling out that Clark may be responsible for other homicides.

"I believe that once you're a serial killer, you're always a serial killer," he said. "I believe there could potentially be more victims out there."

Authorities said the investigation is ongoing.