Grand Rapids, Michigan – A Grand Rapids Police officer resigned in the midst of an Internal Affairs investigation of unreasonable force when the officer put the muzzle of his rifle up against the head of the prone suspect. (Video below)

Police responded to a report of an armed robbery at a CVS pharmacy with a suspect possibly being armed with a handgun, according to MLive. Two Grand Rapids police officers apprehended the suspect with the use of a Taser. The suspect fell to the ground when Officer Kevin Penn approached and put the muzzle of his rifle against the head of the suspect.

“This is a gun, if you move, you possibly could be injured, do not move, does that make sense to you?” Officer Penn told the suspect. The suspect said yes. Penn told him not to move as the other officer put on the handcuffs.

“The suspect is moving his head and you can see the muzzle of the rifle actually moving the skin/scalp on the suspect’s head, forcing his head down,” the Internal Affairs report said, according to the news site.

The report stated that when the suspect asked what he did, Officer Penn said, “You didn’t listen to us.”

The suspect complained to the officer that he was in pain and said, “It hurts, bro.”

Officer Penn responded, “Yes, it does.”

The Internal Affair report said the officer should have released the pressure of the rifle from the suspect’s head.

“Officer Penn’s decision to press the muzzle against the suspect’s head is not based on any training done at the Grand Rapids Police Department, or subject control principles. When taken with the comments he makes while doing so, it has the appearance of being punitive and retaliatory in nature … ” the report said.

Officer Penn was placed on administration leave on Sept. 12 pending termination for mistreatment of the reportedly armed robbery suspect. Officer Penn resigned six days later.

The man who reported the armed robbery told police the suspect punched him in the face and told police the suspect could have had a gun. No gun was found. Surveillance video showed the suspect assaulting someone in a video.

The 28-year-old suspect, who told police he was homeless, was arraigned two days later on charges of assault and resisting arrest, according to court records.

Watch the video here: