UPDATED at 10:20 a.m. Thursday

ST. LOUIS • A man was shot in the back as he drove on Interstate 55 at about 2 p.m. Wednesday, police said.

The victim, 23, was driving southbound along the interstate approaching Holly Hills Boulevard when a black Cadillac CTS pulled next to his vehicle. A passenger of the Cadillac fired multiple shots into his car.

The victim swerved and struck a pickup truck, which was also traveling southbound, causing it to roll over and strike two light poles, police said.

The Cadillac sped away.

The victim suffered multiple gunshot wounds. He was taken from the scene in an ambulance. Police say he was stable, but his medical condition was unavailable.

The driver of the pickup that rolled over suffered minor injuries and declined medical treatment, police say.

Investigators believe the victim and shooter know each other. The investigation is ongoing, police said.

The scene is close to where two other homicides have taken place along the interstate.