DETROIT -

Police are investigating a shooting that occurred early Saturday morning on northbound I-75 in Detroit, causing the highway to shut down for hours.

According to Michigan State Police, a woman was killed in the shooting. 

A courtesy patrol driver spotted an SUV idling on the shoulder of northbound I-75 near Mack Avenue just after 3:30 a.m. Saturday.  When the driver approached the vehicle, they spotted bullet holes on the driver's side of the vehicle and found a woman inside.  She had been shot and was dead, police said. 

I-75 closed between Mack Ave. and Warren Ave. for police investigation

MSP tells Local 4 that the victim was found in a white GMC Yukon Denali. The victim was identified late Saturday afternoon as Jennifer Ann Scavone, 32, of Sterling Heights.

An unnamed source tells Local 4 they heard about 15 to 20 gunshots coming from the area of the scene at around 11 p.m. Friday night.

The motive behind the shooting is unknown, but some Detroit freeway drivers said it could be a case of road rage.

Dajuan Nelson said it would not surprise him if that was the case.

"No, not surprising. We kind of get a little desensitized to the news today. It seems like things are on an incline, increasingly getting crazier," Nelson said.

Dawud Abdur-Rahmaan said he tries to keep his cool while behind the wheel.

"I think we need to slow down and be very cautious, take the easy road, smile, wave, apologize, I'm sorry, whatever you can do to let that guy know it's not that bad," Abdur-Rahmaan said.

So far, no arrests have been made.

State police are asking any witnesses to contact them.

Witnesses can also call Crime Stoppers of Michigan at 1-800-SPEAK UP.

Police are using K-9 units to search for clues