By real mystery, I mean that there is a correct answer, but if you accuse the wrong person, the game is just gonna roll with it.
Oh! so you mean like Zombie Society - Dead Detective by Lu Muja? I like the idea, but also in that game is proper evidence collection and brainstorming a conclusion. I was expecting that to be the kicker of your game, but I understand and see how multiple endings could be a part of a real mystery.