Each play is self-contained and tells the story of a murder. Actors narrate the play. Before they begin, several people in the audience are given parts to read. They receive a few pages of the script with their parts highlighted and they are requested to "stand and read the part at the appropriate time" No one has to learn lines and all of the speeches are short and easy to read and say..
We can also bring in professional actors to play all the parts. Half way through the play, after the murder has occurred, the suspects have been identified and their motives established, the narration stops and the audience has a chance to discuss the crime amongst themselves, review what was said, ask each other questions and write a solution either individually or in informal groups. The investigator collects thesolutions, continues the narration and the crime is solved.