Cold Cases Solved: DNA Identifies 1970s Killer

Pennsylvania state police announced Wednesday that DNA evidence has linked two unsolved homicides from the 1970s to a single suspect. Authorities identified James Richard Clark Sr. as the perpetrator of both crimes. Clark was born in 1957 and died at age 66 in 2023. He resided in the Washington County area at the time of the killings.

The case began as a standard cold case investigation. In 1976, Susan Rush was found dead in the trunk of her car. Investigators determined she had been sexually assaulted and strangled. The following year, in 1977, the remains of 18-year-old Brenda Ritter were discovered on a hillside. She suffered the same manner of death. Clark was 19 during Rush’s murder and 20 during Ritter’s.

Breakthroughs arrived recently through advanced genetic testing. Cpl. James Petrosky, a criminal investigation assessment supervisor with Troop B, explained that additional DNA work was completed in May 2025. This testing identified the same offender for both victims. Petrosky stated at a Wednesday press conference that the results confirmed a serial killer operated in the region during that period. The families of both victims were notified and requested privacy.

Petrosky noted that investigators have not ruled out other potential victims. He suggested that Clark may be responsible for additional homicides, stating that once an individual is a serial killer, they remain one. Police said they are currently exploring this possibility. The investigation remains active despite the suspect’s death.

Next steps include a review of other unsolved cases in the area that match the crime profile. Authorities will compare DNA profiles from the current evidence against records from other cold cases. They aim to determine if Clark’s genetic signature appears in additional investigations. No new public announcements are scheduled beyond the current release of information.