A man was shot in the back while driving on Interstate 55 Wednesday afternoon.

According to police, the man was driving south on I-55 near Holly Hills when a black Cadillac CTS pulled along side him. Police said a passenger in the Cadillac fired shots into his car, hitting him multiple times.

The victim was conscious and breathing when he was taken to the hospital for treatment. 

After being shot, the swerved and hit a pick-up truck. The driver of the pickup truck suffered minor injuries and refused medical treatment.

Investigators think the victim and suspect are "known to each other." The investigation is ongoing.