Map the scenarios. Assess and reassess the evidence. Eventually, a picture of the crime should emerge as you eliminate possibilities through logic. You may not get the correct answer, but you should be able to discover the most likely scenario.
A key piece of evidence in this case is the long hair found on top of the baking sheet. It is your only piece of physical evidence. The perpetrator must have had long hair. Uncle is bald, while Bob and Mosley have short hair. Aunt, Gina, and the dog all have long hair. With this in mind, your likely perpetrators are whittled down to three. You’ll need to look closer, and to focus your attention on the physical evidence, the hair, its color, texture, and length, in order to find the true culprit.