Updated

Authorities say a 17-year-old boy found fatally shot in the back seat of a police cruiser in Ohio killed himself

The Summit County medical examiner's office says Xavier McMullen died of a gunshot wound to the head and the manner of death was ruled a suicide.

Akron police had said a gun was found next to the teen after the shooting Friday.

Police say the shooting occurred after the teen and two 18-year-old men were arrested as suspects in an armed robbery. Officers say the suspects were placed in separate cruisers. Police Capt. Daniel Zampelli says a gunshot was heard while officers were investigating, and the teen was found dead.

Police say the gun found next to the teen was not a police-issued weapon.