Use "whodunit" in a sentence

1. As she acted like an amateur sleuth and tried to solve the mystery of whodunit, she knew she probably looked like the A-typical tourist but didn't care; she was having the time of her life

2. The American mystery novel: the whodunit novel: is merely a symptom of all the subconscious guilt and fear of punishment and fear of death leaking out of undead entities: into the unsuspecting minds and hearts and souls of living humans

3. “It’s just a classic whodunit

4. I just hope we’ve got proof positive of whodunit in here