A police officer has quit after shocking footage emerged showing him holding a rifle to the head of a handcuffed homeless man, who was screaming in pain.
The bodycam video was taken in Grand Rapids, Michigan, as Officer Kevin Penn responded to a call about an attempted armed robbery.
The suspect, 28-year-old Javonte Howell, had already been tasered and was in handcuffs when Penn pressed the weapon to his head.
Another officer was also pointing a gun at Howell.
Penn told the suspect: "This is a gun, if you move, you possibly could be injured, do not move, does that make sense?"