Chicago police release video of off-duty sergeant shooting unarmed autistic black teen from an unmarked vehicle after chasing him through the neighborhood for looking 'suspicious'

After Hayes (circled red) steps toward Muhammad's vehicle (circled blue), two shots ring out

Video released by an oversight agency shows an off-duty Chicago police officer shooting and wounding an unarmed, autistic man during an incident initially described as an armed confrontation.

Sergeant Khalil Muhammad shot Ricardo Hayes on August 13, 2017 at around 5.05am, as the teen walked on South Hermosa Avenue on Chicago's South Side.

Hayes, then 18, had wandered away from his home and his caretaker called police, informing them he was autistic and missing, according to the American Civil Liberties Union says.

Muhammad, 47, was off-duty, wearing civilian clothes and driving his unmarked personal vehicle when he spotted Hayes wandering the neighborhood.

In a police report, he said he was 'investigating a suspicious person' at the time of the incident.

The home surveillance video shows Hayes sprinting down the street with Muhammad in pursuit in his vehicle.

The teen stops on the sidewalk and  Muhammad pulls up alongside him in the vehicle.

Words are heard, which are indistinct but sound as if they could be: 'What you doing over here, man? Huh, what you running from?'

Hayes takes four steps toward the vehicle, his arms at his sides.

Two shots ring out. Hayes stumbles backwards and runs down the sidewalk.

Muhammad gets out of the vehicle and checks down the sidewalk in the direction Hayes ran, before returning to the car.

The sergeant spends a few seconds moving around outside of the vehicle before getting in and driving off in pursuit.

Muhammad caught up with Hayes and took him into custody, only then calling 911 to request and ambulance, audio from the 911 call shows.

'I'm behind Morgan Park High School, I've got a person down,' Muhammad says, as wailing can be heard in the background.

'The guy pulled - like he was about to pull a gun on me, walked up to the car, and I had to shoot,' Muhammad says.

In a tactical response report filed later that day, Muhammad wrote that Hayes 'displayed a dark object perceived to be a gun'.

The police sergeant also noted in the report that he was filling it out under duress, under fear of losing his job if he disobeyed a direct order to complete the report. 

Hayes suffered minor wounds to his arm and chest and recovered from the injuries.   

Police initially called the shooting an armed confrontation, but Police Superintendent Eddie Johnson later said Hayes had no weapon.

Muhammad remains on administrative leave.