Sounds similar to a murder mystery game I played with my teacher in 8th grade. Basically I was the "murderer" and would write the death of a student every other day, leaving a hint as to who the murderer could be, and the class would collaborate together to guess who it was (which was hilarious when they ganged up on the wrong person). They finally got it when 2/3 of the class was dead, but that's only because I dropped a Pokémon reference and they got me (something about the victim being the very best, like no one ever was).