The demonstrations on Tuesday came a day after coroners say Pierre L. Loury died at a hospital.
Chicago Chief of Detectives Eugene Roy says the teen ran from a car believed to be connected to an earlier shooting. Roy says an officer chased the teen and an “armed confrontation” resulted in the officer shooting Loury.
He says a weapon found at the scene was taken into evidence.
But Loury’s mother has said her son didn’t have a gun. The boy’s stepfather says the family wants justice, the Associated Press reported.
Local media report the vigil was held at the site of the shooting. Protesters then marched through streets, sometimes disrupting traffic.
The shooting is under investigation.