Det. Sgt. Jeffrey Bouldin said Franklin Hutchison, 68, shot his 67-year-old wife and then their 47-year-old son, William in the residence in North Huntingdon Township, about 25 miles east of Pittsburgh.
The Westmoreland County coroner's office said all three were found shot to death Thursday night. Police were asked to check on the home after the younger man's employer, a car dealership, said he had not come to work for several days.
The gun used in the shootings was found near Franklin Hutchison's body downstairs, while the wife's body was found upstairs in her bed and the won in a hallway near a bathroom, Bouldin said. All three died of single gunshot wounds, he said.
Investigators believe the shootings occurred Tuesday morning because neighbors said the older man always took his garbage out shortly before it was collected on Tuesday morning, and the cans remained along the street, Bouldin said.
He said the motive is believed to have been "a family situation" but declined to be more specific.
"It is very sad, and it's very upsetting to me," neighbor Catherine Savani told WTAE-TV. "The whole family—it's hard to fathom."
Savani said she had not heard anything at the home but had started to worry because the trash cans were still out.
"We were really shocked. You don't think about that around your own neighborhood," neighbor Fred Johnson told the station.