INDIANAPOLIS -- A man was killed late Monday night in an unusual case involving a car and a hammer that police are investigating as a possible homicide.

Witnesses told police that the man who died, Robert McClurg, 49, was hanging onto the hood of a 1999 Oldsmobile Alero that was traveling as fast as 60 mph through a neighborhood on the city's north side at about 9:15 p.m.

Police said witnesses told them that the man was hitting the windshield with a hammer. Another man was behind the wheel, hammering the gas on 40th Street, near Graceland Avenue.

"Apparently an individual was on the outside of the vehicle and fell off the vehicle at some point in time," said Indianapolis Metro police Sgt. Paul Thompson. "Shortly after the individual fell off the car, he was transported to the hospital and was pronounced dead."

Police said they initially thought McClurg was a hit-and-run victim.

"We've gone from the focus of a hit-and-run fatality accident to a potential homicide investigation," Thompson said.

The man who was driving the car was described as black, about 6 feet tall, with a medium build and an orange shirt.

Police speculated that the car might have been stolen from McClurg or that he might have traded the car for drugs.

McClurg's father, Dewey McClurg, said his son had a long criminal history of vehicle thefts and drug offenses. Robert McClurg had struggled with a cocaine addiction for about 10 years, according to his father, and had just gotten out of jail.

"I bailed him out this time and I should have left him in there," Dewey McClurg said. "I … got him out of jail and bought him that car, and for about the 10th time, I thought I'd get him straightened out, but I couldn't do it."

Officers asked anyone with information to call Crime Stoppers at 317-262-TIPS.