->'''Chief Wiggum:''' Hey, I crack cases all the time. Like the case of the symphony conductor who murdered his star cellist.\\
'''Lou:''' That was an episode of ''Series/{{Columbo}}'', chief. They show you who the bad guy is at the beginning of each one.\\
'''Wiggum:''' Yeah, but you have to '''remember!'''
-->-- ''WesternAnimation/TheSimpsons''

Also known as the "open mystery" or "How To Catch Them"; a style of CrimeAndPunishmentSeries show popularized by ''Series/{{Columbo}}''.

The traditional mystery challenges the viewer to solve the mystery along with the detective. Usually, the viewer is disadvantaged by the fact that the detective knows more than the viewer (WeWouldHaveToldYouBut; TomatoSurprise; CluelessMystery). But in the ReverseWhodunnit, the advantage goes to the viewer: we actually get to ''see'' the murder as it is committed.

The "mystery" for the viewer is not "whodunnit" but "howcatchum." We know who, what, where, when, and why, perhaps in more detail than the detective will ''ever'' know. For the viewer, the question is: how will the detective solve what appears to be a perfect crime?

A successful Reverse Whodunnit requires a very intelligent criminal, capable of designing a crime complex enough that its solution remains interesting even if you already know who did it and why.

It also requires a far cleverer detective than you can get away with in a standard Whodunnit, because the writers can not rely so much on misdirection to make his job look hard. For example, solving any ''Franchise/ScoobyDoo'' mystery would be trivial if Velma let the audience get a good look at the clues instead of hiding them until TheSummation.

Sometimes called a "procedural" (not to be confused with the PoliceProcedural), because its focus is on the ''procedure'' rather than the ''solution''.

This was probably invented by R. Austin Freeman in 1912, in his collection of detective short stories ''The Singing Bone'', which featured Literature/DrThorndyke. He called this concept the 'inverted detective story'.

A subtrope of InternalReveal. Compare and Contrast both CluelessMystery and FairPlayWhoDunnit.


[[folder:Anime & Manga]]
* In ''Manga/DeathNote'', [[VillainProtagonist the main character]] is secretly an infamous mass murderer and the series follows his attempts to avoid suspicion from police and a few genius detectives.
* The [[LongRunners long running]] anime ''Manga/DetectiveConan'' does these occasionally to mix things up. Although showing the audience the crime itself is rare, often there's only one likely suspect from Conan's point of view, and he has to figure out how they set up a false alibi.
* ''Anime/{{Monster}}''. In this instance, the hero himself knows who the killer is for almost the entire series, it's just finding and capturing him that's the problem.
* In the ''Franchise/AceAttorney'' manga's first case, the killer is shown in silhouette in the prologue section after the murder.
* ''Manga/{{MW}}'' has Meguro having guessed right that Michio Yuki is the Serial Kidnapper.

* ''Film/LesDiaboliques''. Alfred Fichet is investigating (on his own time) Michel's disapperance, who was killed by his wife and mistress. Alfred Fichet is the inspiration for ''Series/{{Columbo}}'', too.
* The Creator/AlfredHitchcock films ''Film/DialMForMurder'' and ''Film/{{Rope}}''.
* ''[[Film/{{Fracture 2007}} Fracture]]'': "I killed my wife...Prove it."
* ''Film/{{Memento}}'' plays the hell out of this trope. We see who [[spoiler: (supposedly)]] was the murderer and so does Lenny in the very first scene. However, the film goes in ''reverse'', and ''then'' with him only remembering scenes in several minute intervals, as we see the outcome and learn the clues as he does while already being "spoiled" to the ending, because of it going in reverse. For the first half, the viewer is able to string together the various short bits of color and he is not, involving quite a bit of mental work, but we still know more than he does because we can remember it. [[spoiler: However, at the halfway point, all hell breaks loose and the people we and Lenny learn to trust and not trust every few minutes may not be as they seem, especially Lenny himself.]]
* ''Film/{{Frequency}}'' has shades of this. Although, it's less a howcatchem than a howproveit. The main characters find out who the killer is fairly early on...the problem is, they only find this out by collaborating over a 30 year time gap (they can communicate via ham radio). So, they somehow have to prove who the killer is to the cops, with evidence the cops will actually believe.
* ''Film/{{Oldboy 2003}}'' has the villain reveal himself to both the viewer ''and'' the protagonist partway through the film, and challenges the protagonist to figure out his motive for imprisoning him.

* ''Literature/DrThorndyke'' was one of the first to do this; several of his stories will show the killer performing an apparently perfect coverup in the first half, then following it with scientific deduction through the second half. R. Austin Freeman stated that such stories were an experiment in whether it was possible to eliminate what he felt were implausibly melodramatic numbers of possible suspects in detective stories by making it clear from the start who did it and how, but the tension instead coming from whether the reader has spotted ''how'' a detective could find out by studying what evidence the criminal left.
** There are also variations such as ''The Shadow of the Wolf'', in which the narrative cuts between the murderer (a skilled engraver and forger) creating a false trail to try to show his victim has absconded but is still alive, and Thorndyke using [[RevealingCoverup the faked evidence itself]] to trace it back to the murderer.
* These were followed by ''Malice Aforethought'' (1931) by Anthony Berkeley Cox, and most of the Department of Dead Ends stories by Roy Vickers.
* The subtitle of ''Discworld/FeetOfClay'' is "A Discworld Howdunnit", though the actual story is a classic whodunit.
** Although figuring out how [[spoiler: arsenic is being administered to Vetinari]] is crucial to solving the who.
** Unless you're just really good at [[spoiler: trilingual puns. It's a shame Vimes isn't.]]
** [[WordOfGod Word of Pterry]] describes both ''Discworld/GuardsGuards'' and ''Discworld/MenAtArms'' in similar terms, although they're more along the lines of thrillers that happen to star policemen. Both villains ''think'' they're in an open mystery, and that they're the main villain of the piece. [[spoiler: They're not. [[EvilIsNotAToy Their murder weapons are]].]]
** ''Discworld/TheTruth'' is similar, except with reporters as the protagonists.
* Examples from literature, later adapted into films: ''Literature/TheDayOfTheJackal'' by Frederick Forsyth and ''Literature/AKissBeforeDying'' by Ira Levin.
** Although in ''Literature/TheDayOfTheJackal'' the investigators locate the assassin by pusuing a line of investigation based on [[spoiler: a false assumption regarding his true identity]].
* ''Captain Leopold Incognito'' had the variation that the villain (and reader) knew Leopold would be making an undercover investigation, but did not what identity he would be using.
* Used to great effect by Mary Higgins Clark in numerous mystery novels.
* In ''Literature/TheCaliforniaVoodooGame'', almost at the start, we see the villain kill someone to help cover up a theft, but we're not told what the theft is. So not only do we read to see how the heroes figure him out and catch him, but to discover what was stolen. Has two brilliant {{The Plan}}s colliding one from each side.
* ''Literature/TheDemolishedMan'' by Creator/AlfredBester spends its first five chapters showing a man commit an incredibly complex murder, then the rest of the book follows the officer who suspects he did it and is trying to prove it. Subverted a bit because [[spoiler:even the killer isn't completely aware of his own motivation for the crime, which proves to be a pretty big obstacle for the officer to overcome.]]
* By Creator/IsaacAsimov:
** The short story "The Singing Bell" opens with the murder, and then introduces the detective and proceeds to the investigation.
** "The Dust of Death", set in the same continuity, follows a similar pattern.
* Almost everything written by Creator/JefferyDeaver is this - the novels often containing passages told from the point of view of the villain early in the novel, and spend the rest of the story charting the battle of wits between the good guys and the bad.
* The ''Literature/JamesBond'' novels ''Literature/{{Thunderball}}'' and (to a lesser degree) ''Literature/FromRussiaWithLove'' feature villains putting a dastardly plot in motion, and Bond unravelling it.
* An early example is the story ''Ali Khwajah and the Merchant of Baghdad'' in [[Literature/ArabianNights One Thousand and One Nights]]. It's perhaps noteworthy that the criminal in this story is in no way exceptionally intelligent - he just picks a very unsuspecting victim. Still, solving the crime is so easy a child could do it...
* ''Literature/RedDragon'' and its sequel, ''Literature/TheSilenceOfTheLambs''. In both of them, we know fairly early on who the killer is, and learn more details as the FBI protagonists figure out the mystery.
* ''Literature/AnnoDracula'': The heroes are out to catch UsefulNotes/JackTheRipper; the first chapter reveals that he is Dr. John Seward.
* Occurs in the first two ''Literature/ProvostsDog'' books alongside regular whodunnits. In ''Terrier'', it's obvious early on that Crookshank is the one behind the fire opal disappearances, but they have a hard time finding proof. Everyone in ''Bloodhound'' also knows that Pearl Skinner is behind the counterfeits, too, but in addition to evidence they also have a Lord Provost who's ''terrified'' of her.
* Creator/StephenKing's ''Literature/MrMercedes'' is about a retired cop tracking down a mass murderer. The reader knows early on who Mr. Mercedes is.
* Mystery author Creator/MichaelConnelly has indulged in this twice. In ''Literature/TheScarecrow'' it is established very early that Carver and Stone are the murderers of Denise Babbit; the suspense lies in how IntrepidReporter Jack [=McEvoy=] will track them down. In ''[[Literature/TheCrossing2015 The Crossing]]'' it's obvious from the get-go that dirty cops Ellis and Long are the murderers. The mystery lies in why they killed Lexi Parks and framed another man, and how protagonist Harry Bosch will figure it out.

[[folder:Live Action TV]]
* ''Series/{{Columbo}}'' is a [[TropeCodifier pioneer]] for the "howcatchum" style, and the creators invented the term. Rather than puzzle out the perpetrator from a variety of suspects, Columbo always focuses his investigations on the actual perpetrator and uses his unassuming style to amass enough evidence for an arrest.
* ''Series/MrsColumbo'' follows a similar format.
* ''Radio/OurMissBrooks'': The episode "Jewel Robbery" see a criminal break into a jewelry store and flee when the alarm sounds. Miss Brooks, standing around the corner, sees Mr. Boynton look into the broken window. The episode then follows Miss Brooks as she suspects Mr. Boynton, and then catches the actual villain.
* Some episodes of ''Matlock'' were like this.
* ''Series/{{Monk}}'' shifted toward this after its first season.
** Although Monk's recaps still filled in a lot of gaps and would give the audience the context and usually more details of the murder itself.
** This is also played with in some cases. The exact nature of the mysteries vary to the point where what exactly ''is'' the mystery differs between each episode. Sometimes it's "who did it", and sometimes it's "how do they catch them", but sometimes the mystery ends up being "how did they do it?" or "why did they do it?". In most cases it tends to be a combination of two or more of these, but exactly which question is the primary focus differs every time.
* ''Series/DiagnosisMurder'' does this a great deal.
** One fun episode has a killer detailing his "perfect" murder and the audience shown how it plans out. Then the actual crime has ''nothing'' going to plan. Still, the killer gets it done only to be ironically be discovered, not for his many mistakes but because the "evidence" against the person framed for the crime was ''too'' convincing for Dr. Sloane. As he notes, it's hard to believe a smart killer can leave so much behind to implicate him and thus fights to get at the truth.
* ''Series/LawAndOrderCriminalIntent'' used this format occasionally in its first couple of seasons, showing the whole crime at the beginning and (usually) setting Goren and Eames on the culprit and harrying them into showing their hand. Later seasons show the circumstances around the murder, but leave the killer's identity ambiguous.
** Otherwise on ''Franchise/LawAndOrder'', if at first the cold open looks to be setting up a ReverseWhodunnit, with a crime appearing imminent, you can expect that they'll subvert it once the near-victim trips over someone else's dead body, which will be the actual focus of the episode's investigation.
* Variation in ''Series/{{Frasier}}''. One episode starts with an entirely innocent explanation for why a cracked skull would end up under the floorboards of Frasier and Niles' old house, the remainder of the episode consists of the two of them discovering it and totally misinterpreting the evidence.
* The ''Series/PoliceSquad!'' series by Zucker, Abrahams, and Zucker.
* The ''Series/{{CSI}}'' episode "Killer" alternates its point of view between the killer and the [=CSIs=], showing his motivations and attempts to cover up his crime as the investigators get closer.
* The second season of ''Series/{{Dexter}}'' is about searching for the [[SerialKillerKiller Bay-harbor butcher]], who happens to be Dexter Morgan. However, it's less about "How do they catch him" then "How does he fool them".
** Also shows up in the third and fourth seasons of ''Series/{{Dexter}}''.
* Episode six of ''Literature/TheConditionsOfGreatDetectives'' is played this way. When interviewing murder suspects, the cast decide instantly who he was and the murderer, though never out-right confessing, doesn't deny that he was the murderer. The rest of the episode is Tenkaichi trying to figure out his trick: [[spoiler: he never manages to]].
* ''Series/TheWire''. D'Angelo: "Tap, tap, tap." Mcnulty and Bunk: "Fuck."
* The ''Franchise/PerryMason'' episode "The Case of the Lucky Loser" used this: at the very beginning, we see a man follow his cheating wife, then shoot her lover. The man's nephew is accused of the crime, and the family hires Perry to clear the nephew without implicating the uncle. [[spoiler:Subverted when it turns out the shooting we saw wasn't really the murder. The supposed victim of the shooting was already dead, the real victim of the shooting was the murderer, and the shooter was the murder victim. It was complicated.]]
* Many episodes of ''Series/CriminalMinds''.
* ''Furuhata Ninzaburou'' is Columbo in all but name; just before the last act, the titular detective "pauses" the action to address the audience to give them hints as to why he believes that the chief suspect did it, and what evidence there is to force a confession.
* Every episode of ''Series/{{Luther}}'' reveals the villain early on, with the drama coming from how Luther will catch the suspect.
* ''Series/WhiteCollar'' has shades of this. The protagonists usually figure out who the bad guy is pretty quickly, and the rest of the episode is spent on how they catch him.
* This is the whole premise of ''Series/BreakingBad'': Walt is a meth cook starting in the first episode, and the DEA spends much of the series looking for New Mexico's elusive new drug dealers.
* The entire premise of ''Series/{{Motive}}'' is that the viewer is told who the killer is within the first few minutes but you have to figure out... well, the motive. It's not a whodunit, it's a "whydunit". The detectives don't know who the killer is or their motive, but the answer to both is revealed in the ensuing investigation.
* Since ''Series/{{Hannibal}}'' is a prequel to the Hannibal Lector film and book series (barring HannibalRising, which takes place even earlier), the entire series is based around the build-up to Hannibal's eventual capture by Will. They also show us some of the other killers in advance.
* ''Series/StarTrekTheNextGeneration'': In "The Mind's Eye", it's obvious early on that [[ManchurianAgent the Romulans are manipulating Geordi]] to do something against the Klingons, and before the final commercial break we learn the endgame of the plot as well as who their [[TheMole inside]] [[TheQuisling man]] is. The question is whether our heroes figure it out in time.

[[folder:Tabletop Games]]
* How to run investigation adventures with mediums or other character with psychic powers: Sure, we know who did it since our resident psychic/medium/necromancer asked the dead guy who killed him/had a psychic flash and saw the crime happen just as if it had happened in front of his very eyes/is a LivingLieDetector and saw right through the lies of the culprit, but WeNeedToGetProof if we want to avoid an innocent character to whom we have a connection becoming victim of a MiscarriageOfJustice.

* ''Theatre/OedipusRex'' is the UrExample. The audience knows Oedipus killed his own father, but we wait for him to figure it out.

[[folder:Visual Novels]]
* The first case in most ''Franchise/AceAttorney'' games is one of these, with the murderer being shown for the player's benefit in the opening cutscene and then serving as the all-too-obvious WarmUpBoss. The most notable aversions are the third and fourth games' first cases, which are more standard whodunnits [[spoiler:partly because in both cases the real murderer is played much more seriously and continue on to be the game's respective BigBad even after their initial defeat]]. The fourth game's first case even serves as its WhamEpisode.
** Sometimes true nature of the guilty party is obvious when you see them for the first time, but other times they pull a U-Turn and make it someone you aren't expecting. ...Then other times, they'll know that players are expecting a U-Turn so won't give you one, instead making the real culprit the person all the evidence has been pointing to. All in all, the series does all three examples so sporadically that you usually can't tell if you should be looking out for the too obvious culprit, the so-completely-innocent-looking culprit, or the in-your-face culprit.
** On occasion, this also happens with the second cases, such as the first game and ''Dual Destinies''. And even the third case in ''Trials and Tribulations'' shows you the killer at the start.
* The first murder in ''VisualNovel/DanganRonpa'' is an unintentional example, as the victim literally [[CouldntFindAPen writes the killer's name in their own blood,]] but upside-down, and in enough of a way that the non-native English speaking cast mistakes it for something else entirely (as a Japanese audience would most likely assume as well.) Western players, however, would see the clue for what it is right away, and thus the mystery for them is more about ''how'' the killer did the deed, [[TropesAreNotBad which is a far more compelling mystery]].

[[folder:Real Life]]
* Former Attorney General Robert Kennedy once formed a task force known as the "Get Hoffa Squad" whose sole purpose was to find incriminating evidence on Teamster leader Jimmy Hoffa. Three years later, they secured a conviction.
* Another example was the case against Al Capone. It wasn't a question of proving he was behind any particular crime, as everyone knew he was. It was a case of finding a case where his direct involvement in illegal activities could be proven, since he could otherwise claim any particular crime was one of his minions getting out of hand. Eventually they got a conviction... for tax evasion.