LAST EDITED ON 07-23-13 AT 02:26 PM (EST)
Well, no one actually gets killed, of course.
"Orient Express" had everyone participate in one single murder. In "And Then There Were None" one serial killer killed everyone one at a time, faked his own murder, and in the end (since he was terminally ill) committed suicide in a manner to recreate the circumstances of his faked murder, framing the last victim he had killed. Film versions of "And Then There Were None" use the alternate ending created by Christie when she adapted the book for the stage.
In the comedy movie "Clue" one of the alternate endings (later revealed as the actual ending) had it that each murder had been committed by a different killer, the only remaining player who hadn't killed anyone was Mr. Green.
Frankly, if they are going for any of these solutions, it is an entirely scripted and ad-libbed show. But I can forgive that on the grounds that it campy fun and way over the top. It is unfortunate that Gildart has to include it on his resume, but his outrageous hamming it up is part of what makes it work. But he's a poor man's Tim Curry in this regard.