Police oversight officials on Wednesday released body-camera video showing an officer shoot a man suspected of carrying a gun during a chase last fall inside an East Chatham apartment building on the South Side.

The shooting happened about 7 p.m. on Oct. 31 in a building in the 7900 block of South Ingleside.

Officers had been on patrol near 79th and Drexel, where they allegedly saw 23-year-old Derrell Johnson standing in a crowd carrying a gun, Chicago police officials said at the time.

Three officers gave chase as Johnson forced his way into the apartment building and allegedly pointed the gun at one of them, police said.

According to police reports made public Wednesday by the Civilian Office of Police Accountability, Officer Constantino Martinez ordered Johnson to drop the gun, and then fired one shot when Johnson didn’t.

Video shows the officer enter the apartment after Johnson, who appears to run away down the landing.

“He has a gun, it’s got an extended magazine,” the officer yells into his radio as he runs down the stairs.

“Let me see your f—— hand!” the officer screams, opening fire down the stairwell. As he descends the stairs, the wounded Johnson appears to shuffle out of a doorway and lay down at the officer’s orders.

“He’s shot in the back,” the officer says, cuffing the suspect and directing other arriving officers to Johnson’s alleged weapon. “Take a deep breath, all right?”

Derrell Johnson | Illinois Department of Corrections

Derrell Johnson | Illinois Department of Corrections

Johnson was charged with one felony count each of unlawful use of a firearm by a felon; aggravated assault to a peace officer with a weapon; possession of a high-capacity magazine and metal-piercing bullets; and being an armed habitual criminal.

He was on parole at the time and is being held at the Stateville Correctional Center, according to the Illinois Department of Corrections.

No officers were hurt.

COPA released the video at the end of the 60-day window required by the city following police-involved shootings. Their investigators have not made a determination as to whether the use of force was justified.