Robert James McDonald is 5 feet 10 inches tall and about 250 pounds. He has blue eyes, black and gray hair, and a beard.
A right leg injury causes McDonald to walk with a limp, the sheriff’s office said in a news release.
He drives a 2003 white Ford Ranger pickup with damage to the passenger door and a hand-painted green cap with a wooden rear hatch bearing Maryland tag 77H334.
Anyone with information about McDonald’s whereabouts may contact the sheriff’s office at 240-313-2878.