CHICAGO (CBS) – Chicago police said officers shot and killed a man in south suburban East Hazel Crest on Tuesday, after the man rammed a police vehicle.

Undercover Chicago police officers shot and killed 27-year-old Ryan Rogers as he and his girlfriend were leaving their apartment in the 1900 block of West 171st Street.

Chicago police said Rogers rammed a police vehicle, and the officers feared he would run them over with his car, so they opened fire.

Witnesses, though, said Rogers didn’t know they were cops and was trying to get away from them, not to run the officers over.

Around 9:45 p.m. Tuesday, Chicago police were doing investigative undercover work in East Hazel Crest, when they spotted a man and a woman get into a car, and the officers approached to investigate.

Police would not say why Chicago officers were conducting surveillance in East Hazel Crest, or what suspicious activity prompted the officers to approach Rogers and his girlfriend.

Neighbors were upset with the shooting, calling the incident foul play.

“How could you be fear for your life if you swoop up in unmarked truck in front of this man, and then you shoot him in his head? You come out with a pistol. He don’t know who you are. You never announced yourself,” said neighbor Robert Brown. “He shot this dude immediately.”

Asked how he knows the officer did not announce he was the police, Brown said, “How do you know it ain’t true?”

Neighbor Soulja Reign said he saw “unmarked vehicles pull up, shooting. So we never thought it was the police, or whatever, from down the street.”

Police remained on the scene until about 6:45 a.m. on Wednesday.

The Independent Police Review Authority was investigating.