This lesson uses characters from the Harry Potter series of novels as a “hook” to stimulate students' interest in introductory forensic science. Students are guided through RFLP (restriction fragment length polymorphism) analysis using inexpensive materials and asked to interpret data from a mock crime scene. Importantly, the lesson provides an opportunity to discuss limitations of using DNA fingerprinting for forensic purposes and addresses a common misconception that the sophisticated science involved in crime-scene analysis is infallible.