Dr. Riddle

Origin
Dr. Riddle was apparently only a doctor in the sense of his ability to "cure" his own poverty through criminal activity. He was, however, very good at riddles. He gave the police clues about where he would strike next, in the form of riddles. He also enjoyed "riddling" people with bullets, and usually carried a handgun. He was a recurring enemy of Bulletman.

Golden Age Appearances
Bulletman #5, 7