DNA Testing Links Deceased Man to 1970s Pennsylvania Serial Killer Cold Cases

DNA Evidence Links James Richard Clark Sr. to 1970s Pennsylvania Cold Cases

“I believe that once you’re a serial killer, you’re always a serial killer.” With that stark assessment, Cpl. James Petrosky of the Pennsylvania State Police Troop B addressed a room of reporters this past Wednesday, shedding light on a dark chapter in Washington County’s history. State authorities have officially identified the late James Richard Clark Sr. as the individual responsible for two homicides that have haunted southwestern Pennsylvania for nearly five decades.

The breakthrough, as reported by KJLH, stems from advanced DNA testing that bridged the gap between two long-standing cold cases. Investigators allege that Clark—who was born in 1957 and passed away in 2023 at the age of 66—committed these crimes while he was still a young man, aged 19 and 20. By re-examining evidence with modern forensic technology in May 2025, officials confirmed that the same offender was responsible for the deaths of both Susan Rush and Brenda Ritter.

The Details of the Cold Case Investigation

The timeline of these tragic events began in 1976. According to reporting from ABC News Pittsburgh WTAE, Susan Rush was discovered dead, having been sexually assaulted and strangled, inside the trunk of her own vehicle. The following year, in 1977, 18-year-old Brenda Ritter was also killed. Her remains were located on a hillside, and investigators determined that she, too, had been sexually assaulted and strangled.

🧬 DNA testing identified a serial killer as the person responsible for two unsolved murders dating back to the 1970s, according to authorities. Pennsylvania State Police on Thursday said James Richard Clark Sr. sexually assaulted and strangled 21-year-old Susan Rush and… pic.twitter.com/obMRHGFapT

— https://x.com/TND/status/2118908847834218525

For decades, these cases remained unsolved, leaving families and the local community without answers. The recent identification of Clark as the perpetrator provides a definitive, if painful, resolution for the victims’ families, who have been notified by authorities and have requested privacy as they process the news.

Ongoing Searches for Additional Victims

While the cases of Rush and Ritter have been linked to a single individual, the Pennsylvania State Police emphasize that the investigation is far from closed. Cpl. Petrosky made it clear during the press conference that investigators are not ruling out the possibility that Clark may be responsible for other unsolved homicides in the region or elsewhere.

The assertion that there could be more victims highlights a grim reality often faced by cold case units: the long shadow cast by serial offenders. As forensic capabilities continue to evolve, allowing authorities to revisit decades-old samples, the potential for identifying further victims remains a central focus for Troop B. The investigation into Clark’s life and history during the 1970s is ongoing, as police continue to piece together his movements during the time he resided in the Washington County area.

The reliance on DNA to resolve these cases serves as a reminder of the shifting landscape of criminal justice. Modern genetic genealogy and refined testing methods have fundamentally altered how the state approaches historical homicides, moving them from the “unsolvable” category into a space where justice, however delayed, can be served. For the residents of Washington County, this revelation brings a formal end to two of the area’s most enduring mysteries, even as it opens the door to potential new inquiries into the past.