Although largely fictional, the film is based on the real-life investigation into a group of hired killers dubbed by the press as "Murder, Inc." (the film was released under that title in the United Kingdom). It was during this investigation, and the Kefauver hearings, that terms like "contract" (a deal to commit a murder) and "hit" (the actual killing itself) first came into the public knowledge. The gangsters used such codes in case of eavesdroppers or phone tappings by the police.