War es der im 3. Stock?

The story

Olga, a woman of the demimonde, is shot in her apartment. The bullet was deflected by something, otherwise it would have killed Olga. Witnesses heard a noise at 2 p.m. that sounded like a gunshot. Detective Heidenreich investigates and discovers that the perpetrator must have been one of the tenants in the building. He realizes that many people are suspects.