Did the butler actually do it in any of the stories? Yes, he did. According to Mental Floss the first time a butler was the murderer in a detective story, was in 1921, Herbert Jenkins’ The Strange Case of Mr. Challoner. The phrase wasn’t used in this story, however. Neither was it coined in another detective story, written by Mary Roberts Rinehart, called The door, and published in 1930.
So why do we say: “The butler did it”?
“The butler did it” became the butt of the joke after Rinehart’s publication though. Only two years before SS van Dine had published twenty rules regarding detective stories. One of the rules was never to let a servant be the killer. The solution would be too easy. Van Dine wrote that a killer “must be a decidedly worth-while person—one that wouldn’t ordinarily come under suspicion”.
Those twenty rules are actually quite a fun read. Van Dine’s manifesto on detective stories seems to be held in high regard even today. Especially rule number 20 caught my attention. It states clearly what you shouldn’t do when writing a detective. I’ll quote it fully here:
And (to give my Credo an even score of items) I herewith list a few of the devices which no self-respecting detective story writer will now avail himself of. They have been employed too often, and are familiar to all true lovers of literary crime. To use them is a confession of the author’s ineptitude and lack of originality. (a) Determining the identity of the culprit by comparing the butt of a cigarette left at the scene of the crime with the brand smoked by a suspect. (b) The bogus spiritualistic séance to frighten the culprit into giving himself away. (c) Forged fingerprints. (d) The dummy-figure alibi. (e) The dog that does not bark and thereby reveals the fact that the intruder is familiar. (f)The final pinning of the crime on a twin, or a relative who looks exactly like the suspected, but innocent, person. (g) The hypodermic syringe and the knockout drops. (h) The commission of the murder in a locked room after the police have actually broken in. (i) The word association test for guilt. (j) The cipher, or code letter, which is eventually unraveled by the sleuth.
To quote the other nineteen rules here, would go too far, but you can read them here in full. But I do want to leave you with rule number seven: There simply must be a corpse in a detective novel, and the deader the corpse the better. No lesser crime than murder will suffice. Three hundred pages is far too much pother for a crime other than murder. After all, the reader’s trouble and expenditure of energy must be rewarded.
Do you want to know what else you should or shouldn’t do when you want to write a detective? Then sign up for my course starting on Monday September 16th, 2019. https://www.marthapelkman.nl/product/write-and-structure-your-detective-story