There is a short story that focuses on a serial killer in a big city. The police are on his trail, and they think they've finally caught him. However, in the end, it turns out the person they caught was just a copycat who was inspired by the real killer. The real killer is still out there, and this revelation creates a lot of mayhem as the police have to start their search all over again.
Sure. There's a story where a man is suspected of murdering his wife. All the evidence points to him. But at the end, it's revealed that the wife faked her own death to frame him and run away with her lover. The mayhem throughout the story is all about the man trying to prove his innocence while everyone believes he's guilty.
One Murder Mayhem short story has a group of friends on a camping trip. One by one, they start to die mysteriously. Everyone suspects each other. In the end, it's discovered that a wild animal with a strange disease was causing all the deaths. This unexpected ending creates a sense of mayhem as all the suspicions and theories the friends had among themselves were completely wrong.