Why did the culprit murder the victim? For right now, just list the basic motivation and we’ll decide the murder weapon later.

“The key to a great murder mystery is the belief that a sufficiently diligent reader could solve the case. That’s not to say that the reader actually can solve the mystery, just that they believe they could if they spent a bit more time thinking about it.

When the mystery’s solution is announced, the reader needs to be able to trace the story back and recognize a path they believe they could have followed. The fact that the detective put the clues together when they couldn’t is what makes the character impressive. On the other hand, a detective who has access to information the reader didn’t will be considered a cheat, and their writer along with them.” – Bronwyn Hemus