The investigation apparently started after a robbery at a Speedway gas station in the 7200-block of West Lincoln Highway in Frankfort Township on Saturday. The suspect allegedly fled the scene in a silver or blue Jeep.
When deputies responded, they learned of another robbery involving a similar vehicle at a White Castle in Matteson.
Police officers had followed that vehicle to the intersection of Interstate 80 and Interstate 57, where the driver and passenger fled on foot into a wooded area.
K-9 Copper and his handler helped arrest one suspect.
County Club Hills police arrested a second suspect in the parking lot of the Country Club Hills Food and Liquor.
Charges are now pending in the Speedway robbery case.