Police said officers responded to a call of a kidnapping in the 7600-block of South Coles Avenue shortly after 5:30 p.m. It was unclear whether the kidnapping took place in that area, or elsewhere, police said.
Officers saw the 23-year-old suspect on a second floor balcony of an apartment building engaged in an indecent act in the presence of a seven-year-old girl.
The suspect was taken into custody and the girl was transported to Comer Children's Hospital to be evaluated.
Friday police said the 7-year-old girl was with her brothers on at a park, sitting on a park bench. When her brothers' attention was elsewhere, the 23-year-old man grabbed her.
A bystander saw what happened and called 911, even following the man back to the apartment to help lead police officers to them.
Area Two detectives are investigating. Charges are expected soon.