What I try to do is write a story about a detective rather than a detective story. Keeping the reader fooled until the last, possible moment is a good trick and I usually try to play it, but I can't attach more than secondary importance to it. The puzzle isn't so interesting to me as the behavior of the detective attacking it.
Dashiell HammettI distrust a man that says when. If he's got to be careful not to drink to much it's because he's not to be trusted when he does.
Dashiell Hammett