John Hamner was a guard at the Gotham Zoo.
History[]
Hamner was approached by an unknown party about two Alaskan timber wolves at the zoo. He was bribed to leave the wolves' cages unlocked. However, the same person who paid Hamner sent a giant werewolf-like creature to kill him and tie up loose ends. He tried to get away, but he was knocked out. Batman's intervention saved Hamner's life, though the werewolf did manage to throw him in the water. He came to, but when he saw Batman, he fainted again.
Detective Bullock, who was investigating the disappearance of the timber wolves at the zoo, realized Hamner was on duty that night. Combined with the fact that financial records revealed a checking account in Hamner's name showed a sizable increase a few weeks after the animal abduction, caused Bullock to put two and two together, and he arrested Hamner for dereliction of duty, bribery, and being an accomplice to a crime.