CLAYTON, Mo. (AP) - A teenager is facing first-degree murder charges for allegedly killing a 71-year-old St. Louis County man who refused to give up his car keys.

The shooting happened in September but charges were filed in February against 17-year-old Melford Newlon. He is jailed without bond.

Police say Newlon was 16 on Sept. 9 when he and two others approached Steven White in the driveway of a University City home, showed a gun, and demanded White's car keys.

White refused. Police say Newlon shot him once in the head. The assailants took his cellphone and drove away in his van.

When police spotted the van about three hours after the shooting, Newlon allegedly accelerated in reverse toward officers.

A second teenager, 19-year-old Keishon Jennings, has also been charged in this incident. Police say Jennings knew about the plan to rob the victim and watched Newlon shoot him in the head.

Jennings has been charged with second-degree murder, two counts of armed criminal action, first-degree robbery, and first-degree tampering with a motor vehicle.