I NEED AN IDEA FOR A MYSTERY STORY!! PLEASE HELP?!?

i have to write a ten page mystery story for my english class, it's a 10th grade honors course. i must have: a clearly identifiable crime, a detective (must have unique "tags"), clues, list of suspects, plausable motive for the crime, process by which the solution is reached. (there can also be a sidekick, red-herring, and a sub-plot)