At about 5 a.m., police were called to a gas station on the 2100 block of Green Bay Road. There, officers found a man dead in the driver's seat of a 2014 Chrysler 300.
The man is in his 20s and is from Zion. His name has not yet been released.
Shell casings were recovered at the scene.
The motive is not known and no one is in custody.