Stray Dog A film by Akira Kurosawa

When young detective Murakami (Toshiro Mifune) has his gun stolen, his desperate wish to retrieve it sends him deep into Tokyo's criminal underworld. Meanwhile the gun is passed from the pickpocket who stole it to a young gangster and is then used in the killing of an innocent woman. Murakami's guilt and remorse over this death leads him to ask senior detective Sato (Takashi Shimura) for help, and together the two of them do everything they can to find the gun before the killer strikes again.