A Dead Unicorn Trope in murder mysteries, essentially a form of The Dog Was the Mastermind that's too well-known to use.
The stereotypical example is that a bunch of people are invited to a dinner in a wealthy man's house, and the wealthy man is poisoned while they are all eating dinner. All the guests debate who among them is the killer, only to discover at the end of the story that the killer is the butler, whom nobody bothered to think twice about; he's just part of the furniture, as if the table was the culprit.
The butler is the avatar of the most unlikely suspect that, of course, turns out to be guilty because the author wasn't creative enough to come up with a better way to surprise the reader. It's the mystery writer equivalent of the Ass Pull, except that you can see it coming a mile away, making it, for modern readers, The Untwist. Ironically, because this trope is so well known, when an 'actual' butler is involved he rarely 'did it', or when he did then it's often a parody and Played for Laughs.
The expression "The butler did it" was probably coined by novelist Mary Roberts Rinehart, although it's likely to be a real-world example of Beam Me Up, Scotty!. The earliest verified explicit statement of disapproval dates to S.S. Van Dine's 1928 essay "Twenty Rules for Writing Detective Stories" (it might be noted that these rules would disqualify the authors who defined the genre, including Wilkie Collins, Edgar Allan Poe, and Arthur Conan Doyle). This article explores in detail the origin of this strange semi-existent trope.
It is okay, however, for a butler to be a suspect, primarily to mislead the reader.
Not to be confused with A Wizard Did It.
Obviously, ending spoilers follow.
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Anime & Manga
In the Black Butler anime, in almost every other arc this is the case, in the cases Ciel has to solve, it was the butler other than Sebastian that "did it". First it's Grell in the Jack the Ripper arc, then there's no butler, then it's Agni, then it's Ash at the end of the first season.
Invoked in Detective Conan, where the father of a pianist Driven to Suicide by a rich Jerk Ass gets a work as the butler of the old man and uses this to murder him in his birthday party. He also was planning to kill the old man's daughter who was the son's girlfriend, but due to a miscalculation he fails... and it was a good thing, as the girl still loved the son and had become a Broken Bird after his death.
Another episode involved a butler kidnapping a little girl named Akiko. However, it turns out that he was doing it for noble reasons and with Akiko's permission, since her father was a Workaholic and she wanted his attention. Unfortunately, Akiko was kidnapped again, this time by a genuine criminal. After she's rescued, the dad forgives both butler and daughter and grants Akiko her wish, as they go into a vacation together.
In One Piece, Merry the butler survived an assassination attempt on his life. The OTHER butler did it- Klahadore. Real name, the infamous CAPTAIN KURO. Also, Kaya's parents died shortly after he enrolled as a butler...
In Umineko no Naku Koro ni, although the "butlers" are more like servants, this is what Eva suspects during the first arc. During the second arc, Kanon goes missing after he and Jessica are killed in another 'closed room murder', and as he has a master key, Rosa comes to the conclusion that either Kanon (who had disappeared), Gohda or Kumasawa (neither of whom had an alibi) killed Jessica, as they were the only ones who could have locked the door to Jessica's room. As it turns out she was right. Maybe.
In Hellsing, if Sir Islands' suspicions are anything to go by, Walter Dornez - the Hellsing family's butler - had been working for Millennium way before he officially turned, and was responsible for the security breaches that enabled the Valentine brothers to get into the mansion and massacre most of Hellsing's staff. It's also just a tad convenient that he gives Alucard a gun which is later destroyed by the Doktor via remote control.
In Rick Veitch's Brat Pack, Big Bad Doctor Blasphemy, responsible for the deaths of... the entire cast, is revealed to be King Rad's butler Fredo in the final pages.
Played with by Diabolik: the actual'' butler is always innocent, but Diabolik tend to take his place (or the place of another house servant) to take a look of the place he's about to steal from and/or drug/kidnap his victim.
In one number of Zipi y Zape the twins volunteer to investigate who stole from a woman. Their first question is if she has a butler. She has not.
Well, if you had a butler, solving this would be a lot easier.
This is what sets the plot of The Aristocats in motion, pretty much. Butler Edgar is second in line for the fortune his wealthy mistress wants to leave to her cats, and so knocks them out with sleeping pills and tries to get rid of them. This being Disney, the kitties live, and then have wacky adventures before Edgar's comeuppance is delivered. Also played within that the audience (but not the characters) knows it's Edgar right off the bat.
Clue only plays this straight in a fourth ending that was filmed but never used. Two endings are aversions and the third is a subversion, as detailed further down.
No murders involved, but Fitzwilly takes this trope Up to Eleven by starring a butler who's a Con Man criminal mastermind. Subverted in that all the other domestic servants in the household also Did It.
Lawrence from The Princess and the Frog is a lesser villain, but still needs mentioning; He was Prince Naveen's valet on his visit to New Orleans before he became an accessory to Dr. Facilier's plot to feed all the souls in New Orleans to his friends on the Other Side by being magically disguised as the Prince (the real thing being transformed into a frog).It's a Long Story.
In Where The Truth Lies, Lanny believes Vince killed the girl and Vince thinks Lanny is the murderer. It turns out the butler strangled her. The reveal hurt the movie; as one critics noted the ending was "straight out of the big book of mystery clichés".
Gosford Park where a valet/butler tries to kill a wealthy aristocrat, but the housekeeper beats him to it!
Becomes one of the theories/rotating contradictory solutions in Murder by Death, a parody pastiche of classic murder mystery tropes, and is appropriately lampshaded.
Bensonmum: Tell me, as the only survivor, how did you deduce it was me?
Sidney Wang: Went back to theory seldom used today: Butler did it.
While they were never so common as popular belief holds them to be, they're not entirely nonexistent. In Herbert Jenkins' The Strange Case of Mr. Challoner (1921) and in Mary Roberts Rinehart's own The Door (1930), the butler indeed does it.
The butler did it in the Sherlock Holmes story "The Musgrave Ritual", although in that case it's only theft, not murder, and not the mystery; the question is why he did it, and what happened to him afterwards. It eventually transpires that he's dead, possibly at the hands of his accomplice. The maid did it (or at least let it happen).
In The Hound Of The Baskervilles, suspicion initially settles on the butler John Barrymore and his wife Elisa, but both are later shown to be innocent. What they are guilty of, however, is giving shelter and supplies to a fugitive — who turns out to be Elisa's younger brother Selden, a local Serial Killer.
Agatha Christie used variants of this a couple of times; in Sparkling Cyanide, the waiter did it, while in Death in the Clouds, the air steward did it. However, in both cases, this was one of the regular suspects disguised as a server.
In Three Act Tragedy, the butler is the prime suspect, having disappeared soon after the murder. Turns out he did it, but he was one of the other suspects in disguise.
Black Coffee, originally written as a play, has this ending. In the book adaptation, not by Christie, it's spoiled the moment it happens by outright stating, before the detectives even arrive, that the character placed the poison into the victim's coffee cup before giving it to him.
One of Christie's short stories, The Adventure of the Italian Nobleman also employs this trope, except that in this case the "Butler" is actually a Valet.
Subverted in And Then There Were None. The butler, Mr. Rogers, (and his wife) are two of the suspects, but are two of the first victims. They're guilty of something else, though (killing their former boss, a rich and sickly spinster), and that is why they got killed.
In The Dresden Files, it's not exactly the Butler, but has the Beneath Suspicion slot down pat: the traitor on the White Council isn't the Jerkass leader, the mysterious Asian, the noble Native American shaman, the Captain of the Wardens, OR Harry's Jerkass parole officer Morgan - it's Samuel Peabody, the secretary.
The original book version of Roots has a horrible deconstruction of this trope: the white plantocracy needed black house slaves, and therefore surrounded themselves with black butlers, maids and cooks, many of whom had excellent motives for murder. The book recounts how some black nursemaids would stab a pin into the brain of a white baby through the soft spot before the skull bones knitted, leaving the baby in a coma with no visible mark.
Live Action Television
One Jonathan Creek Christmas special actually used this, though, as usual for the series, half of the mystery was realising that it had been a murder in the first place, and then how and why it had been done. The victim was a magician who had apparently killed herself, but it ultimately — and appropriately — turned out that The Butler Did It. How? It was all done with mirrors.
This is used in the Bones episode "Yanks in the UK", seemingly for the sole purpose of allowing them to use that line. On the other hand, it's arguably a subversion: The butler's confession conveniently stops the investigation and spares his employer's family the public scrutiny of a trial; it's unclear if he in fact "did it."
On one episode of The Twilight Zone, a group of people get off a bus and gather at a cafe where they are served food and drinks by the local counter jerk and dine. It is later revealed by the police that one of the people on the bus seems to have been an alien. Ten Little Murder Victims ensues, the resolution of which is only a half-subversion of The Butler Did It: one of the people from the bus was The Mole, but the cafe worker who served them all and remained very much in the background throughout the story was also an enemy alien from a different planet, and was two steps ahead of The Mole the whole time.
Boardwalk Empire: Parlor maid/servant Louanne is the one poisoning the Commodore.
Happens in Lewis and its predecessor Inspector Morse occasionally, most recently in Wild Justice. Never trust a college servant.
The Hardy Boys Nancy Drew Mysteries episode "Dangerous Waters" plays with this: the kidnap victim doesn't recognize her mother's butler when he greets the Hardys at the door. Naturally, he turns out to be part of the plot, and the non-recognition turns into a vital clue for Joe & Frank to crack the case.
Castle, after teasing a couple of times, finally gives us a straight example in "Secret's Safe With Me", finally allowing Castle to say the phrase and have it be true.
It's possible for this to be the case in the game Clue, if Mrs. White is the randomly selected murderer.
In the setting of the role-playing game Over the Edge there is a Milkman Conspiracy of butlers and personal retainers around the world. They usually don't murder their patrons, but if there was a good reason...
In the card game Gloom, the description for Butterfield the Butler is "Whatever it is, he did it."
''Phoenix Wright: Ace Attorney: Justice for All's final case, with Matt Engarde's butler, Shelly de Killer, a.k.a. "John Doe". He's not the victim's butler, though, and in point of fact is less of a 'butler' and more of a 'professional assassin using a butler's position as his cover'.
Carltron, Professor Ruffleberg's robotic butler from Secret of Evermore, is revealed to have been the one behind his disappearance, and also those of several of his contacts.
Early hints in the first episode of Covert Front hint at the butler, Manfred, having done something to his master. At the bequest of his superiors in the Imperial hierarchy, as it turns out.
In a non-mystery example, in Disgaea 3: Absence of Justice, both Mao and the player are lead to believe that Mao's Dad is the game's Big Bad. However, it turns out that Super Hero Aurum in the guise of Mao's butler Geoffrey is the game's actual Big Bad.
Grabbed by the Ghoulies features a kindly old butler named Crivens who helps you out for the majority of the game. When the final boss battle comes about, Crivens rushes in and seems to have things well under control after beating the boss for you. It is then revealed that Crivens staged the entire fight and is in fact was the final boss the entire time.
"Foolish boy! Did you like my little disguise? Bet you never guessed that the butler did it?!"
Hurricanes episode "The Curse of the Gorgon" had the Hispanola Hurricanes seemingly turned into stone by the legendary Medusa. It turns out they had just been replaced by statues and a butler working for the Hurricanes' host had been bribed into helping.
Not a butler but a valet. The legendary spy Cicero at the British embassy in World War II.
William Marsh Rice was poisoned by his butler in a conspiracy involving one of his attorneys and a fake will. The mystery was solved by another of his attorneys, and his university endowment was restored.
A recent case involving leaked letters from Pope Benedict XVI.
The whole trope came into being from the fact that in Victorian England serving staff were more often than not underpaid, overworked and typically disgruntled. Occasional murders of employees thus weren't unheard of. There is a record of a valet who had memorised his master's schedule to the last detail and once brought him his pillow just before he had intended to ask for it. The master, angry at his presumptuous servant, sent him away and called him immediately back to bring him the pillow. The valet shot him.
The third episode of Devil May Cry: The Animated Series, where the butler is the one who uses his master's blood as part of a demon summoning ritual. Partially subverted, in that this doesn't occur until late in the episode, we actually see the butler telling the master, and the master is eventually healed after the demon and the butler are vanquished.
In a Soul EaterBreather Episode, Excalibur tells a tale of how he helped Sherlock Holmes solve a murder in which the butler can clearly be seen twirling around a butcher's knife in the background.
But it was Watson. Excalibur said it.
In Kaori Yuki's Godchild, a flashback chapter has the lead solving a mystery about a maid's murder. It turns out the butler didn't kill her, she died of her own greed and foolishness. He did, however, tamper the evidence to frame someone else.
Really; we can call Detective Conan a "Zig-Zag" of this trope. There are a couple cases where The Butler Did It, but there about as many if not more cases where the butler clearly did not do it.
And even on a couple cases where it looks like the butler or the housekeeper/groundskeeper could have done it because s/he had motive (Namely Billionaire Birthday Blues wherein the two victims had caused the death of the housekeeper's granddaughter) s/he is shown to be above it. In Billionaire..., said housekeeper even delivers a "The Reason You Suck" Speech to the culprit, her granddaughter's suitor who had just invoked Love Makes You Evil as his Freudian Excuse.
There was a Batman story arc where Bruce Wayne was accused of murder. One background character, upon hearing the accusation, commented "He has a butler, doesn't he?".
Later in the same arc, Bruce Wayne escapes custody. The detectives in charge of the inquiry, after piecing various hints together, finally reach the conclusion that "The butler did it", after spending much of the inquiry snarking that it cannot be the butler, because the butler ''always'' does it.
Then there's "Last Rites," a two-part Batman story set during Final Crisis, with one chapter called "The Butler Did It" and the other "What the Butler Saw." It turns out that Alfred the butler is actually the Lump, a telepathic parasite hiding inside Batman's memories as he is used for clone fodder by the gods of Apokolips. It's Grant Morrison, what can we say.
In one of the first issues of Spider-Man, when Spider-Man defeated Electro for the first time and unmasked him, he thought "If this was a movie, I would be saying 'Good Heavens! The butler!" but admitted that he had never seen him before.
Some decades later, during JMS's "Spidey's a New Avenger" arc, he pauses while searching the closet of a HYDRA agent to deliver this line to an empty room, on the grounds that he's waited his whole life to say it.
"You see, Inspector? I was right! The butler did it!"
In Desolation Jones, the Colonel's butler is briefly suspected of being the mastermind behind the crime. Jones remarks "wouldn't it be funny if the butler did it." Nobody gets why he's amused.
Lampshaded in the early MAD private-eye spoof "Kane Keen," in which the detective explains that the butler is as good a suspect as everyone else is since "the butler is always the murderer." He then unmasks the butler as the true culprit: the talking dog. A cop then bursts in, breathlessly exclaiming he's figured out that the butler did it.
Made fun of in Archie Comics once. Archie's dad stays up to watch a movie called "Burglar of Barcelona" and is then called to answer a trivia question on who the burglar of Barcelona is, Kate or Harold. Since Archie's dad fell asleep during the movie and missed the conclusion, he can't answer and it turns out...the Butler did it.
Clue (1985): In one of the endings, "Wadsworth" murdered the singing telegram girl, but then it turns out he's really Mr. Boddy; and the "it" that started the whole thing was Professor Plum murdering "Mr. Boddy" (really Mr. Boddy's butler, much to Plum's disappointment).
Also, in the Clue VCR game, the butler (and narrator) is named Didit. In this case, though, he's not a suspect.
Except for his own murder, which he faked to push the guests over the edge of their paranoia.
In the lost fourth ending, he actually is the butler and murdered everyone out of a sick need for perfection, and reveals he poisoned everyone and locked the doors, then tries to escape in a police car, only to be mauled by a doberman.
In Murder by Death, when the detectives are offering their solutions, one of them claims that it was the butler who did it and then faked his own death. In the end they leave without suspecting the real killer the deaf mute cook.
A variation appeared in the film Short Circuit 2. Johnny Five notices the novel The Hound of the Baskervilles. He begins speed reading through it, pauses halfway and says, "I think the chauffeur did it." He speeds through the rest of he book and, on finishing, says, "He did". Of course, as everybody knows, the murderer was the nephew of Sir Charles, and he had trained a vicious dog to murder the rest of the family in order to claim the Baskerville fortune for himself.
Gosford Park is an exploration of this trope and other murder-mystery-related tropes:
Lampshaded when one character, an American movie maker working on a new murder mystery set in England, calls his studio:
Mr. Weissman: Right, but I think it's clear it's the valet who did it. No, because the valet has access to everybody. No, the valet isn't the butler. No, there's one butler, and there's lots of valets running all over the place. He takes care of people. He's in their rooms at night. He could do it. I mean, the valet easily could have done it.
The cast is separated between "above stairs" characters (the upper-class guests of a shooting party) and "below stairs" ones (their servants). During the first part of the movie, it's revealed that every single above stairs character has a reason to murder the future victim, but he's murdered by a below stairs character, whose motivations are revealed in the second part of the movie. Basically, it's not "the butler did it" but "a servant did it"..
The butler acts strangely after the murder because other characters suspect he's the murderer and since he went to prison for desertion, he fears he'll be arrested even though he's innocent.
Following the trope, the detective who investigates the murder questions the servants, but only on their masters. Later, knowing nothing of the servants, he explains that all of them are free to leave as there's no reason to suspect them. This is justified in the movie by the class mindset of the characters and the way they treat their servants (at best, like wallpaper that serves food).
However, this detective is presented as a total idiot. His assistant does investigates below stairs, but only comes up with the conclusion that the butler didn't do it (which is pretty good compared to his boss).
The 1966 comedy film The Wrong Box had a convoluted series of events centering around a dead body and cloudy circumstances of his identity and death. At film's end the entire cast is being questioned by a police detective - the butler of one household gallantly takes the fall for his master and claims to have killed him. The detective says - everyone now - "The butler did it?!"
The Haunted Mansion lampshades and plays it straight. While the butler did indeed do it Heavily implied that the butler was racist The main character immediately after invokes this trope.
Home Alone 4 subverts and averts this trope. The main character belives that the butler of his dads rich girlfriend helped two burglars (his old enemys) get into her high tech Mansion. He made quite a mess driving them away so everybody belives its just an excuse (he was about 9 years old). It turns out it was the , erm, nice housekeeper who is revealed as one of the burglar's mum.
The loyal butler Cadbury in Richie Rich was framed by the villains for the bombing of the Rich's plane to kill Richie's parents. Since Cadbury also happened to be Richie's guardian in light of Richie's parents being missing, by removing Cadbury from the picture, the villain placed himself as Richie's new guardian so he could effectively isolate Richie from the outside world.
In Dark And Stormy Knight the butler, Jeens, didn't do it, but he was obviously involved in some messy business. But "Those bodies were never found."
In the Jeeves and Wooster story Jeeves and the Feudal Spirit, when Bertie meets the author of the murder mystery he's reading, he asks him who's the killer, and he aswers that it's the butler.
To Say Nothing Of The Dog by Connie Willis plays with this trope. First it's discussed, when time-traveling main character Ned muses that the mystery they're solving is nothing like old-school detective stories, where the butler always does it. It actually becomes a Running Gag in the book, as when he travels to a Genteel Interbellum Setting, people are complaining that it's becoming cliche in stories for the butler to do it. And then in the end, it turns out the running gag is a Chekhov's Gun, and butler really did do it... but the "it" that he does is "elope with the beautiful daughter", not "murder the victim".
In the Agatha Christie novel Three-Act Tragedy, the murderer posed as his friend's butler solely in order to murder him and then fled afterwards in a deliberately suspicious manner, returning in his usual guise as the victim's good friend.
In Murder on the Orient—Express, depending on which solution you believe, the butler did indeed do it along with everyone else in the Calais Coach, including the coach attendant. Poirot and the victim are the only people in that coach who didn’t put their hands on the blade.
And the countess Andrenyi
In Black Coffee, the butler really did do it. However, since this was already a dead horse trope, you never see it coming because the butler never actually does it.
One Avram Davidson story presents a (fictional) crime writer who first used the phrase "the butler did it," and subsequently made a great deal of money off of murderous butler stories. When he stumbles into Butler Afterlife, its inhabitants are inclined to kill him for defaming their profession.
This is specifically forbidden under No.11 of Dine's Rules for writing mysteries.
A spy story written by Eric Ambler in the 1930s has an author as the main character. He gets into a conversation with a senior member of a foreign police force, who turns out to have literary ambitions of his own, but no talent: the cop's idea of a stunning resolution to the cliche-ridden murder mystery he dreams of writing is, in fact, this trope.
In Hell To Pay, John Taylor admits that he was reluctant to suspect the Griffins' butler because it's such a cliche. The butler did do it, but charging him with the crime becomes a bit beside the point when his true identity as an archdemon is exposed.
In Bruce Coville's The Ghost Wore Gray, Chris tells Nina: "I'd say that the butler did it...except this place doesn't have one."
In Death: At one point in Divided In Death, Eve talks to Baxter about his partner Trueheart. Baxter is letting Trueheart handle a case in which a woman was found manually strangled in Upper East Side, New York City. She had a lot of money, a miserable disposition, a huge mean streak, and a dozen heirs who are all glad to see her dead. Baxter then says, "I told him I thought the butler did it, and he just nodded, all serious, and said he'd do a probability. Christ, he's a sweet kid." Clearly, Baxter was just being funny.
There's a short story where the members of the Retired Butler's Club are boasting about how they were each suspected of murder and then cleared by clever detectives even though they were all actually guilty. Then, the club's butler murders all the members.
Discussed in a Sweet Valley Twins book when the twins try to figure out who murdered a young heiress fifty years ago. Their older brother jokes that the butler must have done it because it's always like that in the movies. He was surprisingly close. It was the chauffeur.
Live Action Television
An episode of Police Squad!! has "The Butler Did It (A Bird in the Hand)"; true to form, the butler did in fact do it.
In a televised version of one of the Hercule Poirot mysteries, Poirot and Hastings attend a murder-mystery play. The two agree to a game: Poirot will try to figure out which character is the murderer, and write it on a slip of paper which Hastings will read during the third act. Poirot's paper reads: "The butler did it." The play's butler turns out not to be the culprit, much to Poirot's annoyance, and the Belgian detective spends several minutes complaining to Hastings about bad scripting.
In an episode of Doctor Who that featured Dame Agatha Christie as a character and was itself a murder mystery, Donna Noble at one point quips that "Well, at least we know the butler didn't do it."
In an episode of Saved by the Bell, the show's characters go to a hotel in which a murder mystery is staged for the guests to try to solve. In the end, after exhausting several red herrings, it turns out that, indeed, The Butler Did It — and the episode ends with a character saying those exact words.
In a sketch on The Muppet Show, with Rowlf as Sherlock Holmes, the butler did it. However, because the butler is a Muppet monster, he then eats all the evidence, including the body and the only witness. Holmes therefore concludes that, in the absence of evidence, there was no crime at all (having briefly "deduced" that, in the absence of evidence pointing towards the butler, Watson did it).
Veronica Mars, solving the case in An Echolls Family Christmas, muses that she's ticked because she was "this close" to being able to say The Butler Did It.
Veronica: "But no. It was the butler's son."
The Avengers episode "What the Butler Saw" involved an entire school for butlers, which turned out to be a criminal enterprise. At the end, there's an exchange along the following lines:
In a 3rd Rock From The Sun episode, the aliens attended a murder mystery dinner (thinking it was real, of course) and Tommy suggests this at one point. Harry replies "You think the butler did it? Well, that's a little far-fetched."
In one episode of Monk, the introduction implies that the butler dislikes his new employer, the son of his former, now dead employer, while delivering a drink. Instead of drinking the Manhattan, the employer pulls out a pistol and shoots the butler.
In an episode of The Golden Girls, they're participating in a murder mystery weekend. The accusations start flying for the first mystery, Rose stands up, points to the waiter and the following exchange occurs:
Rose: The butler did it!
Waiter: I'm a maitre'd.
Rose: Thank you. The maitre'd did it!
The Closer had a parody, Lampshade Hanging, and subversion all in one in the episode "The Butler Did It". The butler had confessed to a previous murder and was working on a plea bargain when he apparently committed suicide, and the detectives in charge were looking forward to actually being able to say "the butler did it". Turns out, he didn't; he was likely to expose the true killer, who killed him instead and made it look like a suicide.
Subverted in one Magnum, P.I.. Magnum is following the "killer" of a rich and annoying person. It turns out the rich man faked his own death. When he comes out of hiding the valet holds him at gunpoint until he is well scared. And them shoots him with a stream of water out of a squirt gun.
When the Police Cheif is investigating Peter's murder in Soap one of the main reasons he suspects Benson is because he's the butler (the other being because he's black).
Beckett: Okay Mr. Mystery Writer Man, what's your bestselling theory?
Castle: I'm gonna go with... the butler.
Beckett: The butler?
Castle: That's who we always go with when we run out of ideas.
Played with in a later episode, where it looks like the butler may actually have done it, leading to significant lampshading on the part of Castle. (It's averted at the end - he was merely stealing from his employer.)
Much, later however, in an episode in season 7, a butler, who didn't show up until the very end of the episode, actually did do it. Castle was positively gleeful as they arrested the guy. He even begged Beckett to let him announce it, and of course said the trope name verbatim.
Used in another episode where the killer turned out to be a guy who had turned up in exactly one scene beforehand. Namely, the apparent personal assistant to a near-senile political matriarch.
In an episode of Power Rangers Zeo, this trope is invoked in a murder mystery game set up by Detective Stone.
In an episode of Murdoch Mysteries the butler did not kill the original victim. However, he figured out who did it and, agreeing with the killer's motive, he then killed the witness who could have implicated the original killer.
In one episode of Bones the butler to a British noble family confesses to the Murder of the Week. Bones and Brennan suspect the butler is taking the rap for his employers, but don't have any evidence to prove otherwise. Still, Booth can't resist saying the trope name as a Quip to Black.
Reinhard Mey has a song "Der Mörder ist immer der Gärtner" (The Murderer is Always the Gardener). In the last verse, someone offs the sinister gardener: it's the butler.
Gary Larson drew a Far Side cartoon where two detectives are summoned to solve a murder — at a butler's convention. Punch Line: "I hate to start a Monday with a case like this."
In another Far Side cartoon, a detective points to the Butler as the culprit when a victim is gored to death and trampled into the floor. Just ignore the elephant in the trench coat sitting next to him...
The Aesop Brothers, a National Lampoon cartoon strip by Charles Rodrigues about (non-identical) Siamese twins, once played this as an extended fart joke. The brothers as a Holmes-and-Watson pair are retained to find out who let go a wicked one in the presence of an elderly British nobleman. You can guess the ending.
Seen in Anthony Shaffer's play Whodunnit which begins as a parody of the Genteel Interbellum Setting but is revealed to be a play within a play where a real murder occurs among the actors who were the performers. The actor playing the butler turns out to be the murderer, and the Genre Savvy detective notes how he was at first misled into not suspecting that individual because the Butler is supposed to be a Red Herring, but then realized that the actor expected him to think that.
In Something's Afoot, a musical parody of Agatha Christie's Ten Little Indians and similar plots, the butler is killed before the first act, leading to the title song's opening line, "Something's afoot, and the butler didn't do it!"
There is a murder-mystery Affectionate Parody play out there called The Butler Did It. The show jokingly doesn't even have a butler in the cast and at the very end it is revealed that the maid is the murderer. The show also has a sequel entitled The Butler Did It Again.
Played with in Pv P by having the butler secretly playing the role of "hero". Creator Scott Kurtz explanation of the idea was essentially "if anyone ever discovered the secret lair beneath the mansion, they would obviously suspect the millionaire playboy as the hero's secret identity. Meanwhile, the butler would have skipped town and hired his services out to the next rich employer far away, where he would start his hero gig anew."
In Rare's commercially unsuccessful Grabbed by the Ghoulies, Ghoulhaven's looney master Baron Von Ghoul has a few servants, but all of them aside from the also-mad Dr. Krackpot seem like generally good folk displeased with his actions. It's revealed near the end that Crivens, the butler who seemed genuinely very helpful from the start, was actually Baron Von Ghoul himself in a Latex Perfection mask. Lampshaded when the Baron himself states that he didn't think Cooper expected the butler to have done it.
Definitely played with in MySims Agents. In one part of the story, a fortunite crystal, which is able to let people see the future, is the most-sought part of Cyrus [LeBodreaux]'s estate. However, when Madame Zoe goes into the crystal room for a pre-dinner reading, you find that the crystal there has been smashed! You follow the evidence which leads you to the conclusion that Carl, the zombie butler, was the one who smashed it. However, it turns out that Zoe, a skilled hypnotist, was whispering hypnotic suggestions to him as he slept. Not only that, but it turns out that the crystal in the crystal room wasn't even the real fortunite crystal! Zoe, having foreseen that she wasn't the named inheritor of her uncle's estate, had intended to make people believe the fortunite had been destroyed so that the other potential inheritors would leave, allowing her to keep the estate anyway.
Straight with a twist in Ace Attorney. The butler technically did it—but he's not actually Matt Engarde's butler, he's assassin Shelly de Killer posing as a butler. The player knows this before Phoenix does, so it's a bit of Fridge Horror when you realize Phoenix is in the same house as the kidnapped Maya, but has no idea she's only two doors away.
Subverted in Professor Layton and the Last Specter. The butler did it. But this time it is not the butler, the real one had been kidnapped and locked in a cellar while the mastermind took his place.
Lampshaded in the MMORPG Runescape. During the quest "Murder Mystery" you can talk to gossips about the murder of Lord Sinclair. One of the options you can say is "I think the butler did it" in which case the gossip will say something along the lines of "you've been reading too many murder mystery novels my friend". This does not affect the quest's plot in any way.
One of the few examples that admits that it doesn't really happen is a Daffy Duck cartoon, were, after badgering the butler, Daffy notes that it's never really the butler. (It wasn't the Femme Fatale either; as it turned out, he was in the wrong house the whole time.)
In a classic Chuck Jones cartoon, "Daffy Dilly", Daffy attempts to enter the mansion of an ailing millionaire who has offered a million dollars for anyone who can give him a good laugh before he passes on. After repeated attempts to get past an implacable butler, Daffy invokes this trope to get rid of the butler, and manages to convince the butler that he did do it and flee...
Subverted and lampshaded in a couple of Scooby-Doo cartoons:
In Go Away, Ghost Ship, the Scooby gang has to chase a ghost pirate. Their employer, Mr. Magnus, has a big, creepy-looking butler who is an obstacle into going to see him. At the end of the episode, when the pirate is unmasked, Shaggy is surprised:
Shaggy: And I thought the butler did it!
In Nowhere to Hyde, all clues initially point to the housemaid Helga, but in the end it turns out that all those clues were planted by the real villain, who reveals himself when Shaggy and Scooby accidentally find a true clue.
At the end of the Video GameNight of a Hundred Frights, Shaggy (incorrectly) blames the spooky groundskeeper, who then appears and starts a long rant about how everyone always blames the spooky groundskeeper, including the line "Why don't you just say the butler did it?"
An episode of Mega Man involved Dr. Wily programming one of Dr. Light's new housekeeping robots to kill Megaman. After one attempt fails, Megaman utters, "I have a sneaking suspicion the butler did it". Actually it was the maid.
Parodied in an episode of Cow and Chicken, where the Red Guy presents a mystery story not entirely unlike The Orient Express, to the two title characters. Interestingly while the butler clearly had a motivation to injure his employer with his own denture, Red's reasoning as to why he did it is this. Made weirder by the fact that in the very same episode, he's employed as the family's butler.
Subverted in the Hurricanes episode "Lord Napper of Stepney". Napper inherited his Uncle's fortune on the condition he never plays soccer ever again. It's never been stated who would be the next one to get the inheritance until Napper lost it. Until then, the only people who ever hoped to get the money were a relative and the deceased one's business partner and the two of them ever tried to rid themselves of Napper. In the end, the money went to the valet.
In Spongebob Square Pants' The Great Patty Caper, Spongebob, searching for the key that was stolen, says, "We know you did it! The butler always commits the crime!" to the fish who works on the train that is not a butler.
The Backyardigans play with this in their genre spoof episode, "Whodunnit?". It was the butler (ie. Tyrone with his hair combed) who took the jewels, but only because the lady of the house (Tasha) gave them to him. Turns out it was all a put-up job in order to liven up a dull afternoon.