Norbert Poehlke, Der Hammermörder ('The Hammer-Killer'), was a German police officer who was found, after his suicide in 1985, to have committed several bank robberies and murders. He was tagged 'Hammer-Killer' for his modus operandi of killing car owners and using a sledgehammer in subsequent bank robberies in which he would use his victims' cars as getaway vehicles.
Read more about Norbert Poehlke: The Crimes, Investigation