It happened after midnight on the South Side near West 80th Street and South Ashland Avenue in the city's Gresham neighborhood.
Police say they were responding to reports of shots being fired when they encountered a crowd of people and two men fighting. One of the men, identified as Niko Husband, 19, reportedly began struggling with officers when they intervened.
Police say Husband pointed a weapon at them and they shot him. Police also say they recovered Husband's gun at the scene.
Husband's friends who gathered near the shooting scene Sunday afternoon say he did not have a gun.
The shooting happened about eight hours after police shot and killed another man during an alleged chase on the city's West Side.