Jack was an employee of the vehicle towing and repair service Lee Bros. Towing & Repair in Hill Valley in 1986. He wore glasses. After Emmett Brown, who had amnesia, crashed his steam time car into a STOP sign, Lee Bros. Towing & Repair towed the vehicle to their yard, believing it had been abandoned. When Marty said he thought Jennifer had a way with people, Jennifer replied she didn't think Jack qualified as "people" in this case.