HAMMOND, Ind. -- A K9 trooper with the Indiana State Police is recovering from a gunshot in Chicago and a 34-year-old Gary man is dead following a midnight traffic stop on eastbound I-94.

ISP reports a trooper stopped a Hyundai Elantra for a traffic violation near mile-marker 2.4 at Indianapolis Boulevard in Hammond just after midnight Tuesday.

The report states the trooper requested immediate assistance due to two non-compliant occupants in the Elantra.

The trooper then informed dispatch he was holding the suspects at gunpoint while waiting for backup.

A Hammond police officer and two deputies with the Lake County Sheriff’s Department arrived on scene, at which point authorities say they approached the vehicle.

The report states the driver, later identified as Aaron Barnes, pulled out a handgun before an exchange of gunfire occurred between him and law enforcement.

Barnes was struck and pronounced dead at the scene. His autopsy is pending.

The ISP trooper suffered a gunshot wound to the chest and was taken to Munster Community Hospital. The trooper has since been taken to University of Chicago Hospital for treatment and is in stable condition. The trooper's K9 partner was present at the shooting but was uninjured.

Police say the passenger, a 34-year-old woman, was taken into custody for a 48-hour probable cause hold. She's being held at Lake County Jail. Investigators have two days to submit charges, or the person must be released.

Police say the investigation is in its early stages and more details will be released as they become available.

The identity of the trooper involved has not been released at this time.