I also love an old book by Doug Cushman called ABC Mystery.  (It may be available used if it's out of print.)  I put the pages under a document camera so everyone can see the pictures.  It walks through a mysterious theft of a painting in ABC order.  It has all the elements of a good mystery: detective, witnesses, suspects and clues.  Again, tons of room for interactivity...what clues can you spot?  Afterwards, I choose one student to be the detective.  That student closes their eyes while I give a button to one member of the class.  The detective guesses a student who then has to give clues about who has the button, like "They are wearing red."  It's a lot of fun.  One year, when a student was called on her clue was, "He went that away!"

It's a fun topic.  Good luck!