When you cast a b-list, or heaven forbid an a-list, performer in some kind of crime drama, we already know that actor is the guilty party. Otherwise, they wouldn’t be on the show for just a scene or two. Their parts will have to be significant, and therefore, they are the killer/robber/kidnapper.
As much as I hate to admit it, when I saw Andrew McCarthy (sigh) on Monk, I knew immediately he was “the one that did it.” Yes, that pretty-boy face was indeed guilty. awww.