Gwinnett County police have arrested a Snellville man in connection with the shooting death of a pizza-business worker.

Tremaine Washington, 18, is in the Gwinnett jail after being arrested Sunday, Gwinnett police spokesman Cpl. Collin Flynn said. Washington faces charges of felony murder and aggravated assault in connection with the death of Robert Purcell, 40.

Purcell was found in his car Saturday on the Highway 78 westbound exit ramp to Hugh Howell Road in unincorporated Stone Mountain. The victim’s gunshot wound did not appear to be self-inflicted.

Police were called Saturday to the Marco’s Pizza at 3300 Centerville Highway when Purcell’s co-workers noticed that his car, which normally was parked behind the restaurant, was missing. Also, some of Purcell’s belongings were found in the parking lot. Purcell was homeless and living out of the vehicle he was found in, Flynn said.

The victim was last seen Thursday in the parking lot of the business. He was known to sleep in his vehicle on nights before he worked, Flynn said.

Robbery is a possible motive for the incident, which is still under investigation.