The fourth monkey

Chicago. Early morning. A man dies under the wheels of the bus. His face is mutilated beyond recognition, there are no documents with him. But a white box was found nearby, tied with black twine, and in it - the human ear. Detective Sam Porter understands that this is a sign of the serial killer of U4O ("killer of four monkeys"), who has been working with impunity in the city for ten years. After the next crime, he leaves the inscription "not to commit evil", apparently connected with an ancient parables about four wise monkeys. The flair tells the porter that the things of the deceased, and among them the diary of the killer himself, is a kind of mocking tips, which the maniac intentionally teases the detectives, challenging them