For my Year 8s, they are creating a detective for a murder mystery at the end of the year. One of my colleagues has made some excellent progress with this, and suggested the following videos for exemplar detective styles.
http://www.youtube.com/watch?v=pZiv8vkxMac – Columbo
http://www.youtube.com/watch?v=5DVJEQEdo-c – Sherlock Holmes