How do you feel about cheating?
A novel I read a few years ago edges closer to a cheat. A victim is trapped with her kidnapper, who we later find out is a character known to the novel's protagonist and introduced earlier. The trouble is that the character has a highly distinctive physical trait that anyone would notice immediately -- as, indeed, the protagonist does when he encounters him earlier in the book, to the point where he dwells at some length on the trait. The author, it seems to me, cheats by deliberately not having the victim comment on this characteristic. If she did, of course, the reader would instantly recognize the kidnapper. Instead, the author withholds the information in what struck me, once the identity was revealed, as an unfair effort to create suspense.
These two instances may violate the first of S.S. Van Dine's Twenty rules for writing detective stories . (Of course, rules 3 and 9, to name just two, have been violated countless times in countless good and even great detective novels, and Ed McBain, not to mention Fergus Hume, would probably have had something to say about number 9. )
S.S. Van Dine may be a relic, but do you have your own rules that a crime author must not break? What makes you feel cheated in your crime reading?