Police released a photo of a man wanted for aggravated criminal sexual abuse.
Police said the man was in the area of Ada Park when he followed and approached a group of children.
The man allegedly touched a 6-year-old girl and tried to abduct her. Police said he also invited the children to his home.
The suspect is described as 25-35 years old, between 5-foot-7 and 5-foot-10 and weighing 160 to 180 pounds. He has close-shaven black hair, a beard and brown eyes.
The suspect was last seen wearing a light-colored long-sleeve shirt with green pants pulled up to the knees.
Police asked anyone with information to call them at 312-492-3810.