Authorities say the shooting happened in front of 92nd Street Elementary School in the 9200 block of Grape Street at 9:39 a.m. It was also just outside a polling location there.
A 35-year-old man suffered non-life-threatening injuries. Police say it was a domestic violence incident between the victim and another man, who was not in custody.
The school was not on lockdown because authorities know who the suspect is, police said.
A woman was detained by police, but her involvement in the incident was unclear. The suspect remains at large.