MORENO VALLEY, Calif.—Authorities say a Moreno Valley police officer fatally shot a handcuffed teenager who was armed with a gun.

The Riverside County Sheriff's department said the shooting occurred late Friday.

An officer investigating reports about a group of men carrying guns outside a home spotted a suspect vehicle drive by. The officer tried to stop the car and a man identified as 18-year-old Lamon Haslip of Ontario got out of the car and tried to run away.

The officer caught him and pinned him on the ground to handcuff him. Investigators said another officer arrived and saw Haslip roll onto his side. The first responding officer then backed away from Haslip and said he had a gun. An officer then shot him.

Investigators later found a loaded handgun.