Midnight... Quai de Bercy(1953)

Having recently moved into her new apartment, Irène Cazenave, the widow of a well-known police officer, is forced by one of her husband's colleagues to take part in an investigation. The building's provocative concierge has been found murdered. We watch a parade of suspects, only to learn at the end that Irène killed the janitor under blackmail. She kills herself.