State police said troopers were pursuing the armed robbery suspect out of Frankfort, who led them on a chase into Chicago. The suspect hit a trooper's vehicle on I-94 southbound around 75th Street, then later crashed at 95th Street, ISP said.
No state troopers were injured in the crash.
Four people in the suspect's car took off on foot, and only three were arrested. Police said they also recovered three guns.
The fourth suspect remains at large and should be considered armed and dangerous, according to the Will County Sheriff's Office.