The shooting deaths of four family members in a Pittsburgh suburb Sunday night were a murder-suicide apparently carried out by the family’s oldest teen son.

Beaver County District Attorney Nate Bible told KDKA that the investigation is still in the early stages, but it appears that 19-year-old Clifford Hunt Jr. was the last person shot.

Police arriving at the North Sewickley Township home found the parents, Clifford Sr., 51, and Michelle Hunt, 48, dead from gunshot wounds, and the two teen boys — the 19-year-old and his 16-year-old brother Cody — with grave head wounds. They were taken to a Pittsburgh hospital, where they died.

“There were several weapons were taken from the scene. [We are] still sorting out what weapons were used and on who, trying to piece together a timeline of what might have happened,” Bible said.

Investigators believe that Cody Hunt made a 911 call from inside the home, but the call was abandoned, WPXI reported. The youngest son was a junior at Riverside High School, where he played saxophone in the marching band and was a member of the National Honor Society. The school district said he had applied to the US Air Force Academy and hoped to become a pilot.

The district said it was making counselors available to students and staff, along with therapy dogs.

Bible said it was too soon to speculate on a motive for the shooting.