I think it would be funny to write a murder mystery where not only did every single character involved have an obvious motive to kill this mf, they were actually all attempting to murder him first, but the murder attempts all cancelled each other out all except for one. Two people tried to poison him but the poisons just happen to work as antidotes for each other, and instead of killing him only gave him the shits, and due to having the shits he couldn't go hunting that day like he had planned, foiling the plans of the one who had conditioned his favourite hunting horse to panic and bolt at the cue of a whistle, and the other murder attempt of tampering with his gun so that it would have exploded his whole face off.
The whole mystery isn't about who could have done it or how, but who was the one who got lucky and actually succeeded.
Sherlock Holmes and The Case of Perhaps We'd Best Leave This One Alone, Watson. There Appears To Be An Excess Of Armed Maniacs In The Vicinity.
When I was in high school a friend of mine would host murder mystery dinners once or twice a year. They were the kind you could buy as a kit -- I don't even know if they exist anymore -- and everyone was assigned (or chose) a character, then received a booklet of clues to share. The idea was to spend an evening in a one-shot LARP designed like an Agatha Christie novel.
I was a year above most of them at school so they threw a "goodbye" murder mystery for me just before graduation, and about 2/3 of the way through the game we all realized that everyone had at least attempted to kill the victim. The game then shifted from "whodunnit" to "who succeeded in dunninit" which we all felt was not only super fun but above the usual level of narrative complexity for those games.
After we solved it, we discovered that the game wasn't from a kit -- the host had written it herself and meticulously printed out the booklets in replica style of the kits. It was the best going-away party I think I could possibly have had.
