The officer was sitting in his squad car in the 3200-block of West Argyle Street at about 1:35 p.m. when he accidentally shot himself in the leg, police said. He was able to drive himself to Swedish Covenant Hospital, where he was stabilized and later taken to Illinois Masonic Medical Center for further care.
Superintendent Eddie Johnson left a budget hearing to tend to the officer.
The Civilian Office of Police Accountability will investigate the incident.