There used to be one available through American Girl. We did the one about Molly. I think I still have the game. It was that someone stole the Halloween candy. Each girl had a part to play with a booklet to read out of. We (adults) set the clues up ahead of time and they would go find something out of place with traces of candy, etc. They would come back to the table and discuss who they thought was the culprit.
They did have to be readers. I think we did this for 10 year party.