Pennsylvania State Police are investigating a murder-suicide in Mercer County Sunday afternoon.

According to PSP, the incident happened near East Jamestown Road in West Salem Township between 4 and 4:30 p.m. Sunday. Troopers say a witness discovered the deceased victim and heard a gunshot nearby.

The Mercer County Coroner's office identified that 92-year-old David E. Frew was pronounced dead at the scene from a gunshot wound to the head. Frew's death has been ruled a homicide. 

51-year-old David C. Frew was taken to a hospital by ambulance after sustaining a self-inflicted gunshot wound to the head. He died from his injuries at the hospital. His death has been ruled a suicide. 

Officers with the Greenville Police Department assisted in the incident.