The Mousetrap, writing homework help: Write your own school detective story

Write your own school detective story— without actually killing someone. Whodunit can involve who “killed”
the computer in the lab, who “killed” the chance for everyone to have a promised treat, who “killed” school spirit, who “killed” the pizza in the cafeteria and left only the liver, who “killed” the mascot’s costume.
A school or classroom can be the closed society essential to a mystery. Everyone asserts individual innocence but everyone is suspect. How do you determine the culprit? What are the clues? What are the red herrings? Who discovers the culprit and how?