BOSWELL, Pa. (AP) — State police say an 80-year-old man has been arrested in the shooting death of his grandson over the weekend in western Pennsylvania.

The shooting occurred at about 10:30 p.m. Sunday after 80-year-old Ray Edward Supanick got into an argument with his wife in their Boswell home, the (Somerset) Daily American reported.

Somerset County District Attorney Jeff Thomas said the man went into the living room to reach for a long gun, while the woman sought aid from their grandson Joshua Cale Hillegas, but he was shot in the shoulder when he walked into the living room.

Officials said the grandson fled and collapsed on the back porch. He was pronounced dead at the scene. The woman was able to disarm and subdue the man, authorities said.

Police said Ray Supanick told investigators that he and his grandson were struggling for the gun when his finger slipped down to the trigger area and the gun discharged.

Supanick faces criminal homicide, aggravated assault and other charges. Court documents don’t list an attorney representing him; a message was left Monday at a number listed for him.