ERIE, Pa. (AP) — A man shot and wounded by his friend in an apparently unprovoked attack at a western Pennsylvania gun range has been released from a hospital, authorities said.

It’s still not known what sparked the shooting, which began around 2 p.m. Tuesday while Robert A. Eppley, 26, of North East, and the victim, a 28-year-old Erie man, were taking turns firing a newly purchased pistol, state police said.

Eppley had just fired five rounds when he turned and started firing at the victim, who was standing about 10 feet from him, police said. Seeing the shooting, a 67-year-old man in a neighboring stall opened fire and fatally shot Eppely, police said.

The 67-year-old man was questioned by troopers and was later released. Authorities also spoke with the wounded man. The investigation was ongoing Wednesday, and authorities said it wasn’t clear if any charges would be filed in the shooting.

Investigators have been unable to identify any issues between Eppley and his friend, state police said Wednesday. They say the pair drove to the range in separate vehicles with their girlfriends, and all four were taking turns firing the pistol that one of the men had just purchased.

Eppley was pronounced dead at the scene.