Thompkins was working as part of a survey crew in a wooded area near County Line Road off of Warm Springs Road in Harris County, Georgia on January 25, 2002. He was accompanied by three co-workers, all of whom were approximately 50 feet apart. He was last seen at 1:30 p.m. One of the other crew members looked away for a moment; by the time he glanced in that direction again, Thompkins had disappeared. He left his work tools behind and has never been heard from again. Volunteers searched the area shortly after Thompkins's disappearance. One of his boots was located. A piece of blue fiber, apparently from his pants, was found stuck on a nearby barbed wire fence. Tompkins's other boot was found elsewhere in July, five months after his disappearance. There was no other evidence indicating his whereabouts.