->'''Inspector Gregory:''' Is there any point to which you would wish to draw my attention?\\
'''Sherlock Holmes:''' To the curious incident of the dog in the night-time.\\
'''Inspector Gregory:''' The dog did nothing in the night-time.\\
'''Sherlock Holmes:''' That was the curious incident.
-->-- ''Literature/SherlockHolmes'', ''The Adventure of Silver Blaze''

Sometimes the absence of a thing is a vital clue. For example, the absence of fingerprints on an often-used item makes it clear that the item was cleaned. A tool missing from a set could well be the murder weapon.

This is, in fact, one of the harder aspects of real police investigations. The lack of something is easy to miss. However, you have to be careful. The lack of gunshot residue on a person's clothes, for example, '''does not''' mean that there was not a gun fired, it means that there is no gunpowder residue to find ("The absence of evidence is evidence of absence, not '''proof''' of absence"). Lack of such residue on the glove that an eyewitness saw the shooter use and then dump that is immediately picked up by the police might show that the event was staged, however (as the gloves would have residue and there is no way it might have been removed). Also, in RealLife, people firing a modern semiautomatic pistol often ''don't'' acquire any gunpowder residue on their hands; so while the ''presence'' of gunpowder residue may be evidence of guilt (weak in itself the residue could as easily have been picked up at a shooting range), its ''absence'' does not exclude a suspect.

Can lead to a ConvictionByContradiction situation if poorly handled.

Compare INeverSaidItWasPoison, where someone incriminates themselves by mentioning details which were withheld from the public, and ItsQuietTooQuiet for the audio-exclusive version of this. See also NotProven.


[[folder:Anime and Manga]]
* Often used in ''Manga/DetectiveConan'':
** The daughter of a wealthy businessman has been kidnapped and Conan figures out who the kidnapper is when he remembers that no one reported hearing the sounds of dogs barking the previous night. (For clarification, the [[TheButlerDidIt butler]] who claimed to have witnessed the kidnapping said that the kidnapper climbed down a tree, but the businessman's dogs routinely barked at anyone who got near the tree.)
** A man suspected to be the one who had been randomly attacking women with a mallet is found strangled in his own apartment...except Conan can't find any underwear, shoes, or toiletry there. He quickly realizes that [[spoiler:the apartment belongs to someone else, who removed those items to hide the fact that ''she'', a woman, lived there and was the true culprit]].
* In ''{{Anime/Monster}}'', Johan's crime scenes are "devoid of feeling" -- the kills are executed as coldly and methodically as household chores. In one arc, this enables Runge to determine that a certain murder was [[CopycatCrime committed by a copy-cat]] and not Johan -- [[spoiler:blood spatter clearly shows a man had been [[http://kissmanga.com/Manga/Monster/Monster-40?id=7370 slouched in front of a mirror]], but his body is found several feet away because the killer hesitated upon [[http://kissmanga.com/Manga/Monster/Monster-41?id=7374 seeing himself in said mirror]]. Johan would have killed the man without a second thought, but the real killer -- the man's nephew -- was shocked to see himself in the process of killing]].

* In the first ''ComicBook/JudgeDredd'' comic in Hondo-City, the Hondo-City Judge works out that the assassin he is chasing is a robot because there is no rollmat, no food, no toothpaste, etc., in his apartment.
* This was, oddly enough, used to discover Franchise/{{Superman}}'s secret identity back in the Silver Age of comics. Superman has since started filling his bathroom with all the things needed for daily life, and putting medicines in his locker.
* In the DC one-off "World Without Grownups" (a prelude to ''ComicBook/YoungJustice''), it appears as though all the children in the world have disappeared. However, Batman deduces that the ADULTS were the ones who were transplanted to a parallel earth when he notices that none of his bat-gear has any dust on it (and then proceeds to carbon date everything he can find to back up his hypothesis).

* One of the final reveals in ''Film/{{Rashomon}}'' is that the woodcutter, who at that point was the only person the viewer would be inclined to believe entirely, [[spoiler:stole a valuable dagger mentioned by all the other witnesses]], but the object was never mentioned by him.
* In ''Film/TheUsualSuspects'', the absence of [[spoiler:any cocaine in the cargo ship]] is the first sign that the attack isn't what it first seems.
* In ''Film/{{Memento}}'', Leonard shows Natalie a binder of documents he has pertaining to the attack on and murder of his wife; she comments that it seems awfully incomplete for how long his investigation is going. [[spoiler:Then you find out that Leonard destroyed several pages before the beginning of the film's events, intentionally creating holes that he could exploit to continue seeking his aimless revenge.]]
* In ''Film/TheBourneUltimatum'' when the CIA is looking for whoever leaked Blackbriar to the media, their initial response is to check for whoever's cell phone was in the same location as the meeting place. Pamela Landy notes that what they should be doing is checking who has their cell phones turned off, as no employee of the CIA would be stupid enough to meet a journalist with their phone on but that it would be odd for a ranking officer to be out of contact for that long.

* Literature/SherlockHolmes has supplied us with several examples:
** In the story "Silver Blaze" that gives us the page quote, Holmes points out the vital non-clue of a dog failing to react to a mysterious visitor... when a guard dog ''doesn't'' bark at an intruder it generally means it's someone he doesn't think is an intruder at all.
** The absence of certain valuable deeds is a vital clue in "The Norwood Builder."
* In one of the ''Union Club Mysteries'' by Creator/IsaacAsimov, Griswold points out that the female suspect they are looking for (who has been shown to be fanatical about stockpiling supplies she will need) must be post-menopausal as there were no products for dealing with menstruation in her apartment.
** Another story has Griswold show that a suspect is only pretending to be a writer because [[WriteWhatYouKnow there is no]] ''[[MostWritersAreWriters wastepaper basket]]'' in his apartment, which would have fairly standard for a writer at the time.
* In the ''Manga/DeathNote'' novel ''LightNovel/AnotherNote'', this was the basis for all of Beyond Birthday's clues: "Something that should be there, but isn't."
* The Literature/LordPeterWimsey mystery ''The Five Red Herrings'' turns on the absence of [[spoiler:a tube of white paint]] from the crime scene.
* In the Literature/SwordOfTruth novel ''Chainfire'', after the eponymous spell has made everyone forget that Kahlan [[RetGone ever existed]], Richard tries to use this to convince everyone else that she has. He points to where he says he, Kahlan, and Cara had been walking, and notes that there were no footprints between his and Cara's, which were several feet apart. He tells his companions that this means someone erased Kahlan's footprints. Nobody believes him since, as mentioned, everyone is sure that she never existed in the first place.
* This trope is referenced in the first novel of the ''Bernard Samson'' series. While Bernard is in custody of an East German intelligence officer, they discuss the story of [[Literature/SherlockHolmes Silver Blaze]]. Bernard then points out the equally curious omission of any attempt at a proper interrogation. The reason for it is [[spoiler:that the officer's boss is Bernard's wife]].
* In the ''[[Literature/HonorHarrington Echos of Honor]]'', a State Sec general figures out that the prisoners have taken over the prison because the warden failed to send his next chess-by-mail move in the mail delivered by a courier ship.
* In the ''Literature/TheDresdenFiles'' novel ''Literature/SmallFavor'', Michael suspects that Harry is [[spoiler:under some form of magical influence]] because throughout the whole novel up to that point Harry has [[spoiler:not once used the fire magic that is normally his go-to spell, and the blasting rod he uses to focus his fire magic is nowhere to be found]]. When Harry confronts Michael about his suspicions, Michael is able to prove to Harry that something is wrong by quietly [[ArmorPiercingQuestion asking]] [[spoiler:where his blasting rod is - in fact Harry is under a spell by the Queen of the Unseelie Court to prevent him from using fire magic, and only when Michael brings it to his attention does he realize (along with most readers) that his blasting rod is missing and that he hasn't so much as thought about it or fire magic throughout the novel up to that point]].
** In ''Literature/FoolMoon'', Johnny Marcone knows that Harry has sneaked onto his estate even though (or because) he didn't see him do it: one of his security cameras went on the fritz and he says, "Such malfunctions and Mr. Dresden tend to go together."
* Parodied in the Literature/{{Discworld}} City Watch books, where Vimes notes how hard it is to find something missing because said thing is, by definition, not there.
* In ''{{Literature/Aquarium}}'', a superior asks Suvorov whether he knows what a certain section of the intelligence department is dealing with. Turns out he does -- since he never received any data from them, the obvious conclusion is that these are units which only operate during the war. Combined with the available data about the section's officers, who are all very tall, that means these are recon and sabotage units. Well, the proper name for them is Spetsnaz, but of course that cannot be obtained by deduction.
* ''Literature/TooLikeTheLightning'': Inverted. There is some vague, contradictory evidence that the Utopians were behind the theft of the [[SeriousBusiness Seven-Ten List]] in an attempt to discredit the Humanists and their car system in favor of the Utopians' own car system. When the world leaders ask Mycroft what he thinks, he points out that if the Utopians ''were'' involved, [[ThePerfectionist they would have done it so perfectly that no one would have suspected them for a second]].
* In ''Literature/ArtemisFowl: The Opal Deception'', [[BigBad Opal Koboi]] has a specially constructed shuttle made entirely of "stealth ore" that is supposed to be almost impossible to detect with most conventional technology, in order to evade the authorities. Artemis gets around this by modifying the scanners on his own shuttle to detect unnatural absences of common elements... and very quickly finds what appears to be a shuttle-sized vacuum at the place where Opal is hiding.
* The maid in ''Literature/TheMovingFinger'' looks vainly through the window all afternoon for her boyfriend, but sees ''nobody'', not even a postman - meaning that the poison pen letter occasioning her employer's wife's "suicide" that day did not come through the mailbox.

[[folder:Live Action TV]]
* ''Series/{{Monk}}''
** Monk's very first case was an example of this; a hooker had [=OD'd=] on Promazine -- a tranquilizer for ''horses'', pills the size of an adult's ''eyeballs''. Monk's partner at the time, Stottlemeyer, said suicide. Every cop on the scene said suicide. ''Medical examiner'' said suicide. Monk walks in, says murder. "Where's the water?" The room had no water! Simple. Eight people in the room, but nobody saw that.
** "Mr. Monk Goes to a Fashion Show": Monk proves that a fashion model's apparent suicide by sleeping pills was staged because the victim was wearing lipstick and there are no lipstick traces on the glass she supposedly drank from.
** In "Mr. Monk Goes to a Rock Concert," the clue that suggests to Monk and Natalie that a roadie did ''not'' die of an overdose in a port-a-potty is a lack of mud on his boots that would have been present if he'd walked through the muddy patch around the bathrooms.
** In two episodes, "Mr. Monk and the Astronaut" and "Happy Birthday, Mr. Monk," Stottlemeyer concludes that someone else has been to a victim's place of residence from the fact that a computer is missing.
** In the serial killer case documented in the ShowWithinAShow in "Mr. Monk's 100th Case," this is shown when Monk is at one crime scene, and later turns out to be a clue that allows them to tie the victim to a serial killer:
--->'''Adrian Monk:''' Her lipstick?\\
'''Captain Leland Stottlemeyer:''' Yeah, what about it?\\
'''Adrian Monk:''' It's on the cup. There's some on her lips. But it's not here; it's not in her purse. What happened to the lipstick?\\
'''Natalie Teeger:''' He took her lipstick?
** In TieInNovel ''Mr. Monk and the Dirty Cop'', a senile old man supposedly walked across his wet lawn, stood on a chair, scaled a fence, and jumped into his pool to kill himself. Monk proves that it was murder because the man's socks would have been stained crossing the grass, and the socks were bleached white when the body was found. Also, the chair would have sunk into the ground under the weight of the victim, but it was simply standing on top of the grass.
* In the ''Series/StarTrekDeepSpaceNine'' episode "The Nagus", one of the things that tips Odo off that Zek is not dead is the absence of his bodyguard Mairhar'du (from a species known for their absolute devotion to their masters) at his funeral.
* Played for laughs in ''Series/{{Friends}}''. Joey gives Chandler his show reel in order to be considered for an advert being produced by Chandler's company. When Chandler claims to have watched it, Joey says that he obviously hasn't, because part of the audition tape was a {{Japandering}} advert Joey did for "Ichiban Lipstick for Men", which Chandler would have definitely made fun of.
* On ''Series/{{CSI}}'', when a serial killer strikes Las Vegas, killing women with towels, causing white cotton fibers to get all over the crime scene, the [=CSIs=] spot a [[JackTheRipoff copycat]] due to the lack of said cotton fibers.
* ''Series/{{Columbo}}'': The episode called "The Most Crucial Game" has the culprit caught when [[spoiler:Columbo found that the phone call the killer claimed to have made at 2:29 pm in his stadium box (and recorded by a bug on the line) '''lacked''' the sound of the half-hour chime of the anniversary clock in the box]].
* ''Series/{{Raines}}'' uses this in the episode "Reconstructing Alice", with a dog that didn't bark, as in the Sherlock Holmes story. Raines even quotes Sherlock Holmes when realizing this.
* ''Series/LawAndOrder'' had a case where they realized the killer was following the instructions in a book about how to kill someone and get away with it ("for educational and entertainment purposes only," of course). When they caught the killer and confronted him with all the things he did to (successfully) avoid leaving any clues as to his identity, he responded, "So I'm guilty because you don't have any evidence?"
* ''Series/DoctorWho'':
** "The Sontaran Stratagem": UNIT and the Doctor are investigating ATMOS, a factory they believe is a front for alien activity. While Martha examines the workers and the Doctor sonics the ATMOS, Donna finds something suspicious: an empty file folder for sick days. As Martha manages to determine while doing medical checkups on the ATMOS factory workers, this is because all of them have been hypnotized by the Sontarans (as evidenced by one who says in a never-changing pitch that he works 24 hours a day, and has an abnormally high pulse rate).
** It is pointed out in a later episode that the Doctor erasing all evidence of himself from the universe created this as a side effect: there is now a huge "hole" where he was that is obvious to anyone that's looking.
** When [[spoiler:Clara gets erased from the Doctor's memories]], he is able to reconstruct most of what happened by the shape of the absence left behind.
* ''Series/{{Psych}}'': GentlemanThief Pierre Despereaux was never caught and couldn't have been convicted even if he had been because he never left any evidence behind. It turns out the reason he was able to do this was because he never actually stole anything; he just made deals with museum owners so they could collect the insurance money.
* In an episode of ''Series/CityHomicide'', the body of Matt's mother is found on a construction site, fourteen years after she disappeared while buying balsamic vinegar from a local shop. When the team realise she was found without said balsamic vinegar, they conclude that the shopkeepers lied about her leaving the shop.

[[folder:Visual Novel]]
* ''Franchise/AceAttorney'':
** ''VisualNovel/ApolloJusticeAceAttorney'':
*** In the flashback trial, Klavier says that, because there weren't any fingerprints found on the gun, the defendant had to be the killer, because he's known for wearing gloves. Anyone with common sense, however, would know that this is faulty logic, because it could be anyone with gloves (and, in fact, Valant also wore them in the night of the crime).
*** The victim's insulin syringe in the flashback case is completely empty, adding weight to Phoenix's claim that the killer cleaned it and put something else in it.
** In the extra case from the [[UpdatedRerelease Nintendo DS remake]] of the first game, ''VisualNovel/PhoenixWrightAceAttorney'' (MAJOR spoiler): [[spoiler:Damon Gant has just "proven" Ema Skye pushed the victim to his death using a fingerprint-laden piece of cloth he personally cut from the victim's vest. However, Phoenix notes that while the victim died of a pierced lung and was coughing up blood on himself for a while before death, the piece of cloth has NO blood on it. Since this proves the cloth was cut BEFORE the victim was killed, Gant is [[OhCrap a bit unnerved]]]].
** ''VisualNovel/AceAttorneyInvestigationsMilesEdgeworth'':
*** In the first case, the killer claimed to have lost his keys and asked a security guard to open the door to "his" office for him. The absence of the security guard's prints on his door suggests that [[spoiler:he tricked her into opening a different door that she thought was his]].
*** In case 5, the absence of blood on the hilt of a knife that was found inside a victim suggests that [[spoiler:the hilt was switched, as there were several knives with hilts and blades that fit each other]].
** In the third game's second case, the emergency buzzer at the crime scene, which was pressed at the time of the murder, had no traces of prints on it. This is used by Phoenix to prove the victim didn't press it, but the real killer did, resulting in the trope name almost being mentioned.\\\
In connection to the above, later on, the absence of prints is used by Luke Atmey to show that it was Ron who pressed the buzzer, seeing as how Ron was in his Mask☆[=DeMasque=] outfit, which meant he was wearing gloves. [[spoiler:This statement by Luke would come back to royally bite him in the butt, as there's no way Luke should have known Ron was wearing the outfit; that bit of evidence had only been revealed in the earlier part of that day's trial (and not mentioned since), and Luke had been in a completely different courtroom at the time.]]
** Comes up occasionally when using the Mood Matrix in ''[[VisualNovel/PhoenixWrightAceAttorneyDualDestinies Dual Destinies]]'', most prominently when [[spoiler:Athena and Blackquill team up to trick Fulbright into an "emotional" confession that was anything but]].
** ''[[VisualNovel/PhoenixWrightAceAttorneySpiritOfJustice Spirit of Justice]]'':
*** Played with in "The Magical Turnabout". [[spoiler:Trucy's fingerprints were found in an X-shaped tape understage [[note]]The tape's purpose was guiding the victim to the coffin. He ended up in the wrong coffin because the tape had been moved[[/note]], so the prosecution claims she touched it during the murder to have the victim in the stage, not backstage... but she was wearing gloves at the time, meaning she left the prints sometime before the murder]]. In a nutshell -- something that shouldn't be there, was, which proves nothing in this case.
*** Double subverted in "Turnabout Time Traveler". At one point, you have to prove that [[spoiler:Sorin didn't enter the hold in the night of the crime, and you do that by presenting the hold keycard entry. Because his name is not in the list, he didn't go in. Then Sorin says that he came in using Nichody's keycard. And ''then'', Nichody himself claims that Sorin didn't go to the hold after all, which is the truth]].
* In ''VisualNovel/HigurashiWhenTheyCry'', Rena noticed that the bottle of soy sauce in Rika and Satoko's house was missing, and deduced the possibility that they had visited the Sonozaki estate that night with the empty bottle and been kidnapped.
* In ''VisualNovel/NineHoursNinePersonsNineDoors'', [[spoiler:the Ninth Man's missing bracelet. It leads Junpei to believe that it was used in Snake's murder, and that killer [[LoopholeAbuse could open the door with Snake alone, as the bracelet would replace the third person]].]]
* In ''VisualNovel/VirtuesLastReward'', Sigma and Phi use a variation of this involving Dio's behaviour, or lack thereof, to show that the likelihood that he [[spoiler:killed Luna]] is pretty low. With it being in Dio's nature to make a point to draw blame away from himself, the fact that he didn't ask [[spoiler:where Luna would be unusual if he killed her. On the other hand, when they where going to go through the chromatic doors, only for Sigma and Phi to refuse, Dio got agitated, saying they were gonna get them all killed. In that situation, if he didn't know anything about Luna's killing, the natural thing for him to have said was Luna isn't present and so they can't go through even if they wanted to [since Luna was in Sigma and Phi's trio for that round].]] These two lack of behaviours lead Sigma and Phi to conclude that Dio [[spoiler:was a witness but didn't do the killing.]]
* This is how [[spoiler:Teruteru]] is exposed as a murderer in ''VisualNovel/SuperDanganRonpa2''. After [[spoiler:the blackout, which was when Byakuya]] was murdered, Mikan fell over and landed in a... [[InnocentFanserviceGirl compromising]] position. [[spoiler:Teruteru]], [[LovableSexManiac of all people]], failed to comment on this... [[spoiler:which proved he wasn't in the dining hall as he had pretended but under it, from where he stabbed Byakuya]].

[[folder:Western Animation]]
* In the ''WesternAnimation/JusticeLeague'' episode ''[[http://dcanimated.wikia.com/wiki/Hereafter Hereafter]]'', Superman is apparently killed by Toyman's latest machine, but Bruce refuses to believe it, and presents his theory to Alfred by saying the lack of evidence is what tipped him off--Toyman's weapon left no trace evidence. It left no debris, so it didn't blow him up. It left no scorch marks, so it didn't incinerate him. It didn't even leave ''radiation'', hence it didn't disintegrate him. Bats decides that since Toyman is merely an obnoxious MadScientist, not a god, the [[NoConservationOfEnergy Law of Conservation]] is still in effect, and therefore Superman couldn't have just been destroyed. His conclusion; it teleported him somewhere. [[spoiler:He's right - Supes was shunted forward in time]], but the show doesn't make it clear whether or not Batman is [[NotSoStoic simply in denial]].
* One ''ComicStrip/USAcres'' cartoon (from ''ComicStrip/GarfieldAndFriends'') has Roy steal the cow Orson was supposed to milk, but was too busy reading mystery novels. Orson and Bo launch an investigation. Their only lead is three sets of footprints. Closer to the end, Orson points out the three sets of footprints which to him indicate three suspects. Bo points out that if Orson's theory is correct, someone's footprints are missing: the cow's.

[[folder:Real Life]]
* The [[http://en.wikipedia.org/wiki/Bielefeld_Conspiracy Bielefeld Conspiracy]] {{meme}} parodies UsefulNotes/ConspiracyTheories which run on this. Basically, it posits three questions to the person: Do they know anyone from Bielefeld, have they ever been to Bielefeld, and do they know anyone who has been to Bielefeld. Since most people are expected to answer no[[note]]Bielefeld is a mid-size town in North Rhine-Westphalia, Germany, with no particular thing to attract attention to it and no particular dialect that's really distinguishable from Standard German[[/note]] [[AppealToIgnorance it is concluded that Bielefeld doesn't exist]]. People who answer "Yes" to the questions [[WithUsOrAgainstUs are said to be working for the conspiracy]], or to have been deceived by it.
* A standard intelligence technique when contacting an agent suspected to be compromised is making an innocuous statement or question and expecting a specific response, also innocuous. If the agent is under duress or has been replaced, the absence of the right response is an indication something may be wrong.
* The redaction of confidential words and phrases from documents can potentially backfire, if the non-obscured context of the redaction makes it clear what ''sort'' of information it must contain. It may even foster speculation that's more damning than whatever the actual redacted statement might have been.
* Political scandals often work this way: Some document or thing is questioned. If the person does not address its contents, speculation runs rampant, because after all, if it were innocuous, the easiest thing would be to release it to the press and get it over with. May lead to an underwhelmed reaction when the real thing finally gets out and does not live up to the speculation.
* [[https://en.wikipedia.org/wiki/Abraham_Wald Abraham Wald]] famously applied this trope during UsefulNotes/WorldWarII. A research group tasked with improving planes' armor analyzed the bullet holes after successful missions and suggested adding armor to the places they most often appeared. But Wald pointed out that, since all the planes they were looking at had ''survived'' their mission, their damage would appear most often in places that ''didn't'' need armor, and the correct action would be to add armor to places these planes were ''not'' damaged.