The ambitious criminal Rico heads the East and joins Sam Vettori's gang with his friend Joe Massara. While Joe leaves the gang after that, Rico soon becomes the leader of the gang and also known as Little Caesar. When Joe witnesses Rico murder the Crime Commissioner Alvin McClure, Rico forces Joe to leave his girl friend Olga to return to the gang, otherwise he will kill both of them, which leads Olga to provide information of the gang to the police. But it's time Rico discovers that he cannot kill his friend by himself.