After discovering a slaughtered corpse, the investigating team of the Tokyo Metropolitan Police Department began canvassing the area around the crime scene. As a result, they found a wallet with bloodstains that seemed to belong to the victim, a woman's wallet that did not fit the field, earrings, and other valuable materials, which led them on a foot search. The woman's purse had been picked up by a male prostitute on the subway, and from the prostitute's testimony, they were able to identify the pickpocket's face, but the next day, the man was found dead in a road accident, apparently murdered.