Anyone done a murder mystery night? (Home grown)

[El Moose Monstero]

Just looking to see if anyone has actually done a home-written murder mystery thing; in principle I imagine it to be very similar to running a D&D sort of game or something like that, which I have done (not well, admittedly) before, but it's something I've been thinking about doing for a while since my housemate came back with a cheap murder mystery box from the charity shop. Obviously I'm googling for resources at the moment about the best way to go about it, but if anyone has any hints or tips, or just general advice, or has any 'this is the best website ever for it' recommendations, then that would be good.

Going for a pirate theme, loosely based on a cuban missile crisis ish sort of premise, but I'm sitting planning motivations, whodunnits etc and I'm wondering how to make it not obvious who did it, but at the same time laying out all the pieces so that the villain can be caught, but that there's an equally good chance that whoever picks the villain character has a chance to escape.

Any thoughts and advice welcome!

[dworkin]

Having played many of the packaged ones the three keys are humour, everyone having a motive and everybody being guilty of something (just not the murder). The fun of the night is not so much in solving the murder but in the revalation of 6 (or so) humerously sordid tales.