Murder mystery parties are great for groups of people that are generally nice, or if not nice, at least have a sense of humor. I have a few friends,


One real negative person can be upsetting in any party situation. It is too easy for these people to take things personally (which you should NEVER do in a murder mystery party). It is all about having fun. Scheming to take down (or out!) the competition is what normal people find fun about it.
So if you have a negative person that is going to be offended if you do not invite them to your party, the best thing you can do for everyone is give them a very secondary or even better an extra character. This can help limit their required interaction. Most people won't be gunning for them, unless they start getting nasty. Any guest that gets nasty outside of their character will experience one of two things depending on the group they are in. They will either be completely ignored and avoided, or people will conspire against them and treat them rudely (in character of course

Extra characters can participate as much or as little as they want. This is why we suggest them for shy or angry people. Hope this helps you. I have never personally experienced this (knock on wood), and I am very thank for that.