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.
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. And, as indicated in the page quote, a dog failing to bark at an apparently unknown intruder suggests that the dog was probably familiar with whoever it was.
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. 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 Real Life, 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 Conviction by Contradiction situation if poorly handled.
Compare I Never Said It Was Poison, where someone incriminates themselves by mentioning details which were withheld from the public, and It's Quiet… Too Quiet for the audio-exclusive version of this. Contrast Not Proven, where the police or the prosecution don't have enough evidence to convict a criminal, and Orgy of Evidence, where suspicions are raised due to the presence of too much evidence. See also Appeal to Obscurity, where something being unheard of is used to make a point. Suspiciously Clean Criminal Record is a sub-trope.
- In the Ace Attorney manga case "Turnabout Power vs. Supernatural Power," the final evidence Phoenix uses to prove that Princess Tengu murdered Casper Sly is the lack of an over-capacity alarm when Power Tengu stepped into the elevator, proving Sly was already dead and being suspended from the elevator shaft to make it look like he was standing.
- BNA: Brand New Animal: When examining the explosion at the Sylvasta lab Ogami notices a period where there was no scent in it. As everybody has their own unique scent it was simply a matter of finding the person with no scent to find the bomber.
- Often used in Case Closed:
- 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 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 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.
- Great Teacher Onizuka: When Fuyutsuki goes missing, Makoto notices her apartment is too clean for someone who's been gone for a week, determining that she's been kidnapped and the kidnapper has been coming back and cleaning the place. Her stalker Teshigawara is a Neat Freak, and he quickly gives himself away through his suspicious behavior.
- In 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 committed by a copy-cat and not Johan — blood spatter clearly shows a man had been slouched in front of a mirror, but his body is found several feet away because the killer hesitated upon 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.
- Gallifrey: A major factor in the inquiry into Romana's actions on Gryben, as Narvin claims that the alleged 'timeonic fusion device' with which she was threatened could not possibly exist. It turns out that he's just been covering up the fact that he himself built one and allowed it to be stolen centuries earlier.
- EC Comics: In "Fall Guy for Murder" from Crime SuspenStories #18, a man hires a detective to find his wife who he claims took everything she had and ran out on him. The gumshoe immediately becomes suspicious when he sees that literally every last thing she had ever owned was missing; every piece of clothing, every single pair of shoes, every last hat, all of her luggage, etc. As he notes, a lady running away from her husband on the quick would leave behind something she wouldn't bother taking. It turns out to be a set-up.
- In the first Judge Dredd 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 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.
- It's used in Superman: Earth One, when Lois is doing some digging into Clark Kent's life. Because he spent his childhood trying not to stand out in any way at all, not making any friends and just performing averagely at school, it tips Lois off that he's hiding something.
- In the DC one-off "World Without Grownups" (a prelude to Young Justice), 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).
- The premise of Anthony J. Crowley, Retired Demon and Airbnb Superhost is that Crowley rents out his flat on Airbnb, and the fic is the review table. Some guests notice how weird it is that while the flat is full of expensive art, they can't find certain essentials, such as plates, forks, lights, or mugs.
The one complaint I have is there’s a weird lack of certain things here, despite the general “luxury” vibe. Went to see if there were any tissues in the linen closet, and there was nothing except one towel with the Gucci snake on it and a giant bottle of hand sanitizer.
- Avengers of the Ring
- In Return of the Avengers, while Barton correctly observes that orcs aren't the type to formally declare war, the fact that they were able to gather their forces without being observed makes it clear that some unknown party is coordinating their efforts.
- In Methteilien, the dwarves deduce that Morgoth is likely attacking a moon with a supply of uru as Thanos's use of the Reality Stone means that he doesn't need to claim resources in the same manner.
- Avengers: Infinite Wars:
- Discussed when the Avengers reflect that they can be fairly sure they're not in their own galaxy anymore as they would have probably seen the various ships flying around at some point if that was the case.
- Later, one of the Sith Acolytes observes that the Avengers can be detected by searching for the void they create in the Force even if they cannot be sensed through the Force directly.
- Children of Remnant: When Pyrrha and Emerald have a fight that demonstrates just how powerful they both truly are, the Vale and Atlas forces meet to discuss it. The entire time, Summer and Qrow are terrified for how Winter will react, as she is easily the most hostile towards the Claimed children. After the meeting ends, they note that she had the worst reaction - she had no reaction at all, which can only mean that she was already planning something before she walked in.
- Danganronpa: In Harmony's Wake: This proves to be the final nail in the coffin for the blackened of the first trial. Timber Spruce claims that after he got sick from the tainted cider, he spent a little time cleaning up the bathroom, and refers to this when suspicion falls on him. But, Sunset points out that according to Rainbow Dash, the bathroom was spotless when she checked it out herself. Given that Timber was supposedly sick from both ipecac and laxatives this should be impossible, proving that he was only faking being sick with the others.
- In the Harry Potter fic "Disrespecting Authority", after Sirius and Remus find the locket Horcrux in Grimmauld Place and learn about the diary, Remus observes that the fact that Voldemort hasn't gone looking for the locket when he has to know about the destruction of the diary is a clear sign that there are more than two horcruxes because someone like Voldemort would be more actively concerned if he lost one of his only two.
- In The Faith Chronicles, the Watchers' Council fake Faith's death with a mystically-created clone. Janet Frasier realizes that the clone is a fake because the clone's stomach is empty; prior to her abduction, Faith had eaten a full steak dinner, which should have still been in her stomach if she'd been killed for real.
- Guardians, Wizards, and Kung-Fu Fighters: Captain Black and Agent Tag realize that Harold Hale's established backstory is fake, because no one recalls having known him during the time he claims he was at school, nor does anyone who should have known his parents remember ever meeting them either.
- Incompatible System:
- Part of what freaks out the Citadel races so much about the missing Relays is that not only are the relays gone, but there's no traces or evidence of who, or what, removed them, or how, and if it wasn't for their records, there'd be no way to tell that the Relays were there in the first place.
- When Batarian "pirates" start disappearing with little to no trace, the Citadel Council takes notice.
- Lay Down Your Burdens: Kushina Uzumaki's file has her marital status and offspring redacted, something Naruto notes basically announces that she was married and had a child.
- The Lightning Strike;
- Harry reflects that he can be sure there is no equivalent to the wizarding world in the MCU for the simple reason that nobody's stepped in to stop him sharing their secrets with SHIELD.
- When Harry goes off the grid trying to find Loki's staff, Baron Strucker muses that he should have realised he should be concerned once Harry dropped off the grid (thanks to Skye's efforts).
- Missing (Miraculous Ladybug): While discussing the obvious tension between Marinette and Lila, Nathaniel points out that with enough digging, it's possible to turn up dirt on pretty much everyone. However, Alix realizes that they've never seen any solid proof of all the good Lila has supposedly been doing. And as active as she's claimed to have been, it's odd that they've never actually seen any articles, pictures or other coverage of the events in question.
- The Petriculture Cycle: Petriculture: The fact that there are no records of Pinkie's family. There's also this:
Twilight: I... I don't want to be right about this, Pinkie Pie, but it seems like the only solution that fits, which is why I’m hoping you can give me that one piece of evidence that I’m missing—something that wraps everything up in a neat, logical package.
Pinkie: I’m sorry, Twilight, but I can't.
Twilight: You don’t want to talk about it?
Pinkie: No, I mean that I can’t give you the missing information you want... because there isn’t any.
- When Reggie Diceman meets her newest spy Nevermore (real name Anthony J. Crowley) in Spirits of the Blitz, Nevermore takes his cigarette out of his mouth and tucks it behind his ear. Halfway through the conversation, Diceman realizes what was strange about that.
Before you tucked that cigarette behind your ear, Nevermore, did I actually see you put it out?
- There Was Once an Avenger From Krypton:
- One of the major plot points of the Labyrinth arc of The Girl Who Could Knock Out The Hulk is Kara being puzzled by how not only does S.W.O.R.D. apparently have no knowledge of Krypton or the Kryptonian Empire, but that while there is an asteroid belt in Krypton's former orbit around Rao/Gliese 3707 and all the other planets Kara remembers are there, the actual mass of the asteroids is nowhere even close to the mass of even one of Krypton's moons, let alone the other moons, Krypton itself, or its sister planet Daxam, not to mention that Kara's best estimates of how long she spent in the Phantom Zone don't give the belt itself enough time to form. Lena's best guess is that maybe time went wonky and Kara was in the Zone longer than she thought, and the explosion was so violent that the remaining mass fell further out of orbit than Kara thought it would, but Kara's still not convinced. Doctor Doom eventually reveals that this is because Kara's actually from a different universe than the one she's currently in.
- When Nico hears of Dark Dan's Bad Future, and how widespread the devastation apparently was, he wonders why there was apparently no actions taken against him by the Olympians or one of the other major players around Earth. Danny speculates that either there was some other cataclysm that took out the others, or that he's potentially more powerful than even he realizes.
- In Eternity in Promise, Adora muses that, logically, there should have been some First Ones that didn't manage to get off of Etheria before Mara sent it to Despondos, from Mara's own rebel forces to the soldiers and guards loyal to the First One leaders to the technicians keeping everything running. Yet there's been no sign of them anywhere on the planet. Not to mention how that, despite the fact that her existence would indicate that there's at least two other First Ones (her parents) out there, she, Entrapta, and Catra are unable to find any sign of them, or even any of their remains at the remains of the sites Horde Prime attacked, despite the sites having plenty of deactivated Horde robots and the remains of clones.
- The Lucifer (2016) fic "Tragic Life Changes" opens with Chloe and Dan being apparently killed in a plane crash, but Chloe is rescued by God as he realises that the event is a deliberate attempt to kill Chloe. While trying to determine the likely suspects, God notes that a key reason for his concern is that he doesn't know who tried to kill Chloe even though he should know the whole plan by his nature, and asks Chloe to provide him with a list of people new to her life in the last year or so to help narrow down the suspects. This allows God to identify Marcus Pierce as an anomaly as he doesn't recognise Pierce's name when he should know the name of every soul on Earth, leading to Pierce being identified as Cain (even if he is clearly working with someone as he doesn't have the power to hide his activities from God on his own).
- With This Ring: The villains eventually adapt to Paul's ability to find anyone and anything on the planet via power ring, and start using magical scry wards to block his ring scans. However, he's sometimes able to find them anyway (such as Dark Druid and his associate, Deacon Blackfire) by having his ring compare what it can detect to the official blueprints of a structure, looking for a gap.
Paul: Ring, match the plans with what we can scan. Let's hope our target hasn't been as clever as they think they have.
Ring: Discrepancy found.
Paul: HAH! 'Oh, he'll never find me if I put up a scry ward'! Sucker!
- In Wrong Road to the Right Place, after Laurel deduces that the List is a list of people in Starling City who can be blackmailed over past misdemeanors, this allows Team Arrow to determine that the man behind the Dark Archer must be one of the city’s elite from five years ago who isn’t on the List.
- In 2 Days in the Valley, assassin Lee Woods plans to get away with his latest job by killing his partner and making sure the only evidence points to the partner by planting the partner's cigarettes at the scene of the crime. A detective investigating the scene says that it's pretty obvious that the cigarettes were left there intentionally to mislead the cops because it's literally the only evidence there while everything else is entirely spotless. The detective doesn't buy the idea that a killer could leave a scene with no trace evidence at all (no hairs, no fibers from their clothes, no fingerprints, etc.) but also "accidentally" leave an entire pack of cigarettes with their DNA.
- Body Double: One of the reasons Scully doesn't become a formal suspect in the murder (besides the fact he's lucky enough to pick up another couple of witnesses on his way to try to help) is that Gloria has an aggressive guard dog, that stops Scully from even getting upstairs. Detective McLean, not unreasonably, thinks this means that Scully wouldn't be able to kill Gloria without drugging or badly hurting the dog, which demonstrates on Scully and the other witnesses that it's prime health just a few minutes later. Which means that Gloria must have been killed by someone the dog knew. The only person mentioned that qualifies is Gloria's husband.
- In The Bourne Ultimatum 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.
- In 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. 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.
- Peppermint: The police and FBI are clued in to the heroine's whereabouts by looking at crime maps, and finding an area in a run-down section of town that is suspiciously free of crime.
- One of the final reveals in Rashomon is that the woodcutter, who at that point was the only person the viewer would be inclined to believe entirely, stole a valuable dagger mentioned by all the other witnesses, but the object was never mentioned by him.
- In Sherlock Holmes: A Game of Shadows, during the climax both Watson and Simza have to find Simza's brother before he can go through with an assassination plot, while Sherlock is out of the room. They've already deduced that the assassin is going to be disguised as one of the guests, and even Simza has little chance of spotting any recognizable markings. However, Watson figures out that rather than futilely looking for physical evidence, they should be looking for something that someone in the assassin's position wouldn't have or be unable to produce: spontaneous reaction. Watson then causes a loud commotion that draws the attention of everyone nearby, but the assassin sticks out by not reacting at all, since he's too caught up in his performance as a calm diplomat to react like a normal person.
- In There Will Be Blood, Henry doesn't laugh with Daniel Plainview over an amusing story involving them getting girls drunk at the peach-tree dance. This makes Daniel suspicious that Henry wasn't even there and that he is impersonating his long lost brother.
- In Tomorrow Never Dies, Henry Gupta sees through James Bond's cover story of being a banker and deduces he's a government agent, based on the lack of any blemishes on Bond's falsified records.
Gupta: I call it "Gupta's Law of Convenient Anomalies" - if it looks Too Good To Be True, it probably is.
- In The Usual Suspects, the absence of any cocaine in the cargo ship is the first sign that the attack isn't what it first seems.
- The Wolf's Call, in the climactic pursuit, rather than try to listen to their enemy to track its position, which would be almost impossible because the thing they're pursuing is a a stealth submarine, the heroes instead listen to where the least noise is coming from to find it.
- Isaac Asimov:
- Union Club Mysteries:
- 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.
- Griswold shows that a suspect is only pretending to be a writer because there is no wastepaper basket in his apartment, which would have been fairly standard for a writer at the time.
- "Evidence": Someone arrives at U.S. Robotics claiming that mayoral candidate Stephen Byerley is a robot because he never eats or sleeps. Subverted when Byerley points out that even if said someone spied on him, all they know is that he wasn't eating or sleeping then.
- Union Club Mysteries:
- 2666: Happens in just about every murder, given how most of the bodies are left in garbage dumps and that witnesses never come forward. What little evidence is found is frequently lost or forgotten.
- In 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.
- In Artemis Fowl: The Opal Deception, 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.
- Bernard Samson Series: While Bernard is in custody of an East German intelligence officer, they discuss the story of "Silver Blaze". Bernard then points out the equally curious omission of any attempt at a proper interrogation. The reason for it is that Bernard's wife is The Mole so has already told them anything important.
- Crooked House: The deceased was killed by switching his insulin with a topical cataract medicine. When the police dusted the insulin bottle, it was totally clean, despite the fact that a medicine bottle that is used daily should be covered in fingerprints of various clarity. This causes the police to conclude that it wasn't an accident, but a premeditated murder.
- In the Death Note novel Another Note, this was the basis for all of Beyond Birthday's clues: "Something that should be there, but isn't."
- Lampshaded in the Discworld City Watch books, where Vimes notes how hard it is to find something missing because said thing is, by definition, not there.
- A specific example in Jingo comes when Carrot notices that several pages have been torn out of a notepad, leading him to conclude that someone didn't want them to read the note, and was smart enough to know they could get an impression from the next few pages. Vimes takes it a step further, and reasons that the person wants them to conclude this, or they'd just have taken the whole pad. Absence of absence of evidence...
- Dragonriders of Pern: In Dragondrums, Piemur is sent to the Drum towers to learn drumming while his voice is changing from puberty. During his time there, he proves skilled and adept at learning the drumming codes enough to piss off the boys who have been there much longer. So, they start bullying him in progressively harsh ways. The final attack on Piemur is when they place grease on some steps they know he would be rushing on to deliver the message. After he slips hard and cracks his head on the stone floor, the culprits clean off the grease. While one of Piemur's seniors doesn't believe him about the greased steps, noting that they were perfectly clean, the responsible one realizes that the steps in question were too clean. The other steps in that staircase were dirty compared to these few ones. They also didn't clean the grease off of Piemur's shoes.
- The Dresden Files:
- In Fool Moon, Johnny Marcone knows that Harry has snuck 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."
- In Small Favor, Michael suspects that Harry is under some form of magical influence because throughout the whole novel up to that point Harry has 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 asking 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 God-Emperor of Dune, Leto II knows his opponents have perfected a device which can hide them from his nigh-omniscient prescience when somebody he knows disappears without a trace and reappears later, and even calls one of the users of the device out for having been stupid enough to think he wouldn't notice. Of course, even his enemies inventing this device was just All According to Plan for Leto.
- Hercule Poirot: In Curtain, Poirot uses this to point out the flaw in Hastings' aborted plan to murder Major Allerton (whom Hastings suspects has dark intentions towards Hastings' daughter) by poisoning him, as wiping his fingerprints off the bottle containing the poison he planned to use would have wiped away all the fingerprints on that bottle, making it obvious that someone had killed Allerton and with Hastings the prime suspect.
- Honor Harrington: In Echoes 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 John Putnam Thatcher mystery Something in the Air, an audit turns up the fact that the murder victim had an established track record for paying cash for everything, but never cashed a check to get that cash (the novel was written before ATMs were common). The police investigation finds the murder victim was a blackmailer, collecting his payouts in cash.
- The Lady Grace Mysteries: In Assassin, Grace notices something odd about Sir Gerald's body; he was supposedly stabbed to death but there's no blood around the wound or anywhere else even though realistically there should be quite a lot. Grace recalls her uncle once telling her that blood flows through a body like a tide (that's how the Elizabethans understood blood flow) and only stops after death. This leads Grace to realize Sir Gerald was already dead when he was stabbed.
- The Lord Peter Wimsey mystery The Five Red Herrings turns on the absence of a tube of white paint from the crime scene.
- Miss Marple: The maid in The Moving Finger 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.
- This trope was crucial to solving the murder at the heart of the James Herbert novel Nobody True, which initially appeared to be the work of a Serial Killer. It turns out that the police had deliberately left out certain key details about what said killer did to the bodies of its victims when talking to the media in order to make a copycat killer easy to spot. This managed to even fool the ghost of this particular victim.
- Sherlock Holmes 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 The Silence of the Lambs, when Lecter gives his fake profile for 'Billy Rubbin', the alleged real identity of serial killer "Buffalo Bill", and can only remember that he had elephant ivory anthrax, Clarice knows that this information is fake because Lecter would never come away with so little information about someone he'd met directly. With this insight, Clarice correctly deduces that Lecter only knew of the real "Buffalo Bill" through second-hand information, allowing her to prompt him to give her another few vital clues.
- Star Wars Legends: New Jedi Order: The Yuuzhan Vong exist outside the Force, and cannot be sensed or affected through it in any way. However, sufficiently sensitive Jedi can sometimes detect the Vong as a hole in the flow of the Force.
- This proves especially handy when dealing with Vong infiltrators who have disguised themselves as members of the galactic races. Their biotech is advanced enough to allow them to fool most detection methods, but if you focus on someone through the Force and feel nothing, that's pretty definitive.
- In the Sword of Truth novel Chainfire, after the eponymous spell has made everyone forget that Kahlan 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.
- Terra Ignota: Inverted. There is some vague, contradictory evidence that the Utopians were behind the theft of the 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, they would have done it so perfectly that no one would have suspected them for a second.
- Whateley Universe: How Tansy manages to find Kayda under an invisibility charm in as said in The Bear, the Bitch, and Everything (Part 3):
Since she was using her invisibility charm to hide from everyone, I attuned myself to the emotional flow of the school and went looking for a void."
- In Where the Crawdads Sing, Chase Andrews is killed falling from a water tower. The first thing Sheriff Jackson notices is that his footprints aren't visible in the muck, leading him to think that Chase was murdered, and the killer destroyed the footprints.
- In one episode of The Andy Griffith Show, one resident of Mayberry reported that his cow was stolen. An expert criminal forensic scientist comes out and wows everyone but Andy with his scientific knowledge. As they analyze the crime scene they identify three different sets of boot prints which the expert says belong to three different suspects. Andy is the only one to notice something important which is missing, the cow's footprints.
- In an episode of City Homicide, 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 realize she was found without said balsamic vinegar, they conclude that the shopkeepers lied about her leaving the shop.
- Columbo: The episode called "The Most Crucial Game" has the culprit caught when 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.
- On 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 copycat due to the lack of said cotton fibers.
- Daredevil (2015): In the season 1 finale, Matt, Karen and Foggy determine where Leland Owlsley has hidden a corrupt detective who could expose Wilson Fisk, by poring through records dug up by Foggy's ex-girlfriend Marci and noting a specific property that Owlsley has delisted without any record of the property being sold.
- Death in Paradise;
- In one episode, automated door records, witness testimony, video footage, and the coroner's report all indicate that an out of shape scientist climbed alone up the side of a volcano at night to monitor some anomalous seismic readings, had a heart attack and died. Humphrey looks at the scene for a minute and asks why he didn't have a flashlight...
- In the 2021 Christmas special, DI Nevill Parker has his "Eureka!" Moment when he realises that the murder victim's apparent suicide recording has no sounds of the sea when he allegedly killed himself on the beach.
- Doctor Who:
- "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 an ATMOS device, Donna finds something suspicious in their filings.
Donna Noble: Oi, you lot. All your storm troopers and your sonics. You’re rubbish! Should’ve come with me.
The Doctor: Why, where have you been?
Donna Noble: Personnel. That’s where the weird stuff’s happening, in the paperwork. Because I spent years working as a temp. I can find my way round an office blindfolded, and the first thing I noticed [holds up an empty binder] is an empty file.
The Doctor: Why, what’s inside it? Or...what’s not inside it?
Donna Noble: Sick days. There aren’t any. Hundreds of people working here and no one’s sick! Not one hangover, man flu, sneaky little shopping trip, nothing. Not ever. They don’t get ill.
Colonel Mace: [grabs the empty binder] That can’t be right.
Donna Noble: You’ve been checking out the building. Should’ve been checking out the workforce.
- 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).
- "Nightmare in Silver": Mr. Clever points out 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.
- "Hell Bent": When 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.
- "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 an ATMOS device, Donna finds something suspicious in their filings.
- Played for laughs in 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.
- Harrow: In "Ab Initio" ("From the Beginning"), Harrow is struggling to prove that Simon's death was murder and not an accident; especially as the data from Simon's Fitbit shows the exact time his heart stopped. Only after a hallucinatory encounter with Simon's ghost does Harrow realise that what the Fitbit isn't showing is also significant. There was no spike in Simon's heart rate before he died, which you would expect if he had fallen off the ferry accidentally, and Harrow realises that Simon had been sedated before he entered the water.
- J.A.K.Q. Dengekitai: One episode involved a Locked Room Mystery wherein a budding fashion designer seemingly killed himself. But said designer's girlfriend notes that a mannequin was missing from the apartment where he died, and J.A.K.Q. realizes that their enemy CRIME used this mannequin to kill the victim by remote controlling the individual partsnote .
- Law & Order 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?"
- The titular detective's very first case as a detective was an example of this;
Stottlemeyer: We're the primaries on a body at a hotel in the Castro. A hooker had swallowed a bunch of promazine - you know, the big sleeping pills?
Disher: Horse tranquilizers, sir.
Stottlemeyer: I said suicide. Every cop on the scene said suicide. Medical examiner said suicide. Monk walks into the room, 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, meaning that the killer wiped the glass down then put it back in her hand.
- 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 Show Within a Show 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 Tie-In Novel 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.
- The titular detective's very first case as a detective was an example of this;
- Motive: In "Creeping Tom", when the police arrive at the scene of the crime, they find the Body of the Week is guarded by an angry guard dog that barks at anyone who tries to approach the body. Later, Angie realises that while the dog barked at all the police, it did not bark when the intruder was in the house, meaning it was someone the dog knew and trusted.
- NCIS has used this a couple of times:
- In one episode, the killer is a retired forensic expert, meaning the team is left with no evidence whatsoever on the crime scene and are completely in the dark as to finding anything that could lead to a suspect, until Gibbs realize that only a professional would have been able to make the crime scene so clean, which severely narrows down the list of suspects. Then, the expert's attempt at deflecting suspicion away from him leads Gibbs to definitely pin him down as the culprit because of the sudden evidence that popped up and this expert claimed to have found.
- In another case, the team proves that a Navy K-9 handler has replaced her drug-sniffing dog with an attack-trained dog by the fact that the dog does not alert to the small bag of cocaine that McGee has in his coat pocket.
- In The People v. O. J. Simpson, Robert Kardashian's belief in his friend O.J.'s innocence is eventually broken not by the evidence for his guilt, but the fact that even with all the publicity of the trial, no plausible alternate suspect or theory is ever offered.
- In the Poker Face episode "The Stall", Charlie sniffs the victim's beer bottle trying to see if it was dosed with anything, but smells nothing (and realizes that she wouldn't be able to recognize the smell of poison anyway). But then she realizes that she smelled nothing, when she should at least be able to smell beer, meaning that the bottle was washed out. She further realizes that during the portion of the killer's radio show they were using as an alibi, there were no background sounds of a train that passes through every quarter hour, and thus should have been audible on the broadcast.
- Psych: Gentleman Thief 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.
- 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.
- Remington Steele: In one episode, a group of mystery buffs enter a game where they dress up as their favorite fictional detectives and run around Los Angeles trying to solve a make-believe mystery. After a while, it turns out the mystery is real, the bodies are piling up, and the game headquarters where the players call in to "report their progress" is nothing but an empty office with an answering machine. After listening to all the leads and clues that were recorded on the answering machine by the players, Laura realizes that one of the players never left a message, and deduces that they must be the one collecting the messages.
- Star Trek: Deep Space Nine: In the 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.
- Star Trek: Picard: The series premiere opens with a scene of Picard playing poker with Data and declaring that he's found the "tell" that gives away when Data is bluffing. Sometimes, Data dilates his left eye a bit... but that's a fake tell intended to fool others: his real tell is keeping an absolutely steady expression.
- Vera: In "Tuesday's Child", Vera realizes that a story that the Victim of the Week had left of his own accord is false when she searches the victim's hold-all and discovers that he hadn't packed his insulin. As she puts it, why would he leave behind the one thing he depended on for survival?
- Whodunnit? (UK): In "Final Trumpet", the clinching piece of evidence for the sergeant investigating is the lack of muddy footprints on the pristine white carpet inside the caravan. Only one suspect could have entered without using the door, and thus avoid tracking mud in from outside.
- Black Coffee: The lack of dust on the box of poisons, when everything else on the bookshelf was covered in dust, leads Hercule Poirot to conclude that someone had accessed the poison well in advance. Thus the murder must have been pre-planned and not spur of the moment like everyone assumed.
- In Persona 4, this is one of the things that points to the killer. The killer managed to push the first two victims into the deadly TV world, yet nobody saw anyone suspicious approach them, nor was there any evidence found during the excruciating police investigations afterwards. Similarly, the killer dropped off two threat letters at the home of The Hero, yet nobody suspicious was seen approaching your home. Thus, the evidence points to somebody Beneath Suspicion, someone who would have valid reason to approach the two victims, dispose of any evidence that leads back to him, and whom could go to your home without looking out of place. This narrows the suspects down to, of all people, Adachi.
- Invoked as part of the hunt for the "Identity Thief" in Batman: Arkham City; the killer's third discovered victim has had all trace evidence left by the killer destroyed with bleach, but Batman is able to track the traces of bleach used to find a vital witness.
- This is actually a big part of game sense in Multiplayer Online Battle Arena titles (Dota 2, League of Legends, etc.). These games typically come with a mini-map that displays the entire level, with icons showing the location of every enemy you can see, but some of the map — and possibly, some of the characters — obscured by Fog of War. If those enemies aren't visible on the mini-map, what does that mean? Who knows... but the wise player expects trouble. (This is then exaggerated by various characters that have Invisibility Cloaks and can disappear from the minimap no matter what they're doing.)
- Spider and Web: When your equipment is brought to the interrogation room, examining it will list what's there. Some items are missing, which is a clue as to how to proceed.
- Star Control 2: Spoofed by the Spathi and their insistence that some kind of ULTIMATE EVIL exists. Their "proof" that the ULTIMATE EVIL exists is that they've never detected any hint of its existence, which must mean it's hiding just beyond the range of their best sensors, which is proof that it is evil.
- Ace Attorney:
- Apollo Justice: Ace Attorney:
- 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), not to mention the fact that the crime took place in a hospital, where gloves are commonplace.
- 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 "Rise from the Ashes", the extra case from the Nintendo DS remake of the first game, Phoenix Wright: Ace Attorney, Damon Gant has just "proven" Ema Skye pushed Neil Marshall onto a spear using a fingerprint-laden piece of cloth he personally cut from Marshall's vest. However, Phoenix notes that while Marshall was impaled and was coughing up blood on himself for a while before death, the piece of cloth has NO blood on it, meaning Gant had to have cut the cloth after Ema pushed Marshall but BEFORE the latter was impaled. Gant becomes a bit unnerved at this.
- Ace Attorney Investigations: Miles Edgeworth:
- 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 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 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. 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 information 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 Dual Destinies, as it can easily notice that you're not feeling a certain emotion you claim to be feeling. The best example would be when Athena and Blackquill team up to trick Fulbright into an "emotional" confession that was anything but.
- Spirit of Justice:
- Played with in "The Magical Turnabout". Trucy's fingerprints were found on an X-shaped tape marking understage with the tape's purpose being guiding the victim to the right place to stand. He ended up in the wrong coffin because the tape had been moved, so the prosecution claims she touched it during the murder to have the victim on 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 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.
- The Great Ace Attorney:
- Jezaille Brett literally disposes of the evidence already shown in court in the same spot by feigning clumsiness on her part. Which in turn provides another instance of this trope that foreshadows a plot twist: Jigoku, the trial's judge, was in on the assassination scheme that Brett was carrying out in Japan; he'd been a Reasonable Authority Figure up to then, so why did he let Jezaille's antics pass without comment?
- In case 2 of the first game, the blank pages in the report book suggest Strogenov was absent from his post, because when he was present he always wrote "Nothing to report" every thirty minutes.
- In case 4 of the second game, Ryunosuke figures out that Gregson's time of death wasn't what was previously thought to be, due to his time of death being omitted from the autopsy report.
- Genshin Asogi's ring was found in Klint van Zieks's stomach during his autopsy, suggesting that he swallowed it moments before dying. However, the ring has spiky claws that would definitely have torn his digestive tract if he had swallowed it... yet no damage was done. That's because the ring is fake evidence "discovered" by the coroner when he took it out of his own pocket while no one was watching.
- Apollo Justice: Ace Attorney:
- In the first trial of Danganronpa: Trigger Happy Havoc, this is how Makoto convinces everyone he's not the one who murdered Sayaka. The murder took place in his room, and the corpse is in his bathroom, which causes everyone to suspect him. However, Kyoko noticed that his floor was cleaned, meaning there's no hair on the floor that can be used as evidence to identify the real killer. Makoto points out that even if he was the killer, there would be no point in cleaning his room of hair, because it's his room, so finding strands of his hair on the floor would be expected. The lack of hair proves someone who didn't live there killed Sayaka and cleaned the floor to get rid of evidence that might implicate them. While this alone isn't enough to expose the real killer, it does get the rest of the cast to stop pointing fingers at Makoto.
- This is how the first murderer is exposed in Danganronpa 2: Goodbye Despair. After the blackout, which was when Byakuya was murdered, Mikan fell over and landed in a... compromising position. Teruteru, of all people, failed to comment on this... which proved he wasn't in the dining hall as he had pretended but under it, from where he stabbed Byakuya.
- This crops up multiple times across the franchise in regards to the Monokuma Files: Any time the file fails to mention a particular piece of information that's normally present (usually the time of death or cause of death) chances are very good that it'll turn out to be integral in solving the case, and the characters quickly figure out that if Monokuma deliberately leaves something out, they should probably take note. Specific cases include:
- The final case of Danganronpa: Trigger Happy Havoc: The time of death isn't mentioned, because the murder is fake and the body has actually been dead for a while, and while the various injuries to the body are described, none are actually listed as the cause of death, because if the students had realized that Mukuro Ikusaba had died in the same way they'd seen Junko die, they might have realized that a) Mukuro was killed right at the start, and b) Mukuro was posing as Junko at the time.
- The fifth case of Danganronpa 2: Goodbye Despair: The cause of death is absent, despite a number of visible injuries because the death was unrelated to any of them; the victim was actually poisoned and the other wounds are a Red Herring. Chiaki actually calls Monokuma out on this, stating that the cause of death couldn't have been the obvious one, because he wouldn't have bothered to leave it out if that was the case.
- The second case of Danganronpa V3: Killing Harmony: The students almost immediately note that the time of death isn't included, which tips them off that the victim died long before it looks like he did.
- In a non-murder example, this is how Shuichi of V3 realizes there's a secret passage in the library; all the bookshelves had books stacked atop them except for one, which turned out to be hiding the passage.
- This becomes a contradiction in the fan case The Empty Turnabout during Marston's testimony when he claims that he and Ian Arts struggled over Marston's handgun, because the gun only has Marston's fingerprints.
- In Higurashi: When They Cry, 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 Nine Hours, Nine Persons, Nine Doors, the Ninth Man's missing bracelet. It leads Junpei to believe that it was used in Snake's murder, and that killer could open the door with Snake alone, as the bracelet would replace the third person.
- Queen of Thieves: In Jett's first season, this is how he and the heroine find the safe behind a Concealing Canvas in Hugo's house. The heroine had noticed that the wall painting was the only thing not covered in dust — because it was regularly moved.
- In Virtue's Last Reward, Sigma and Phi use a variation of this involving Dio's behaviour, or lack thereof, to show that the likelihood that he 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 where Luna would be unusual if he killed her. On the other hand, when they were 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 was a witness but didn't do the killing.
- RWBY: People with silver eyes are powerful warriors with supernatural abilities, but this is a very rare trait. When Maria's father investigated the lineage of people with silver eyes, he found so little information that it made him suspicious. He concluded that such powerful bloodlines being so rare and under-reported meant that something was actively wiping them out. As a result of this suspicion, Maria spent her life hiding her identity by always wearing a mask and being known solely by a nickname instead of her actual name. Her father was proven right when her efforts failed to stop minions of the Big Bad from tracking her down and trying to assassinate her for having silver eyes.
- Brainchild: Sometimes, the most suspicious thing is something that's too normal. Normal people don't make everything they do consciously and perfectly average to some ludicrously fine detail - but a paranoid conspiracy would.
- In Grrl Power, this is lampshaded with Sydney's orbs occasionally, as they cannot be scanned by most if any means. Dabbler's scanning spells can't even detect the light they give off. At one point an alien killer robot apparently makes her a priority target because it just sees a black void where an orb would be.
- To Prevent World Peace: How Rhea and Chronos know about the other's presence since their powers can't be used to see anything related to the past/future of the other.
- It's mentioned in Vexxarr that being completely hidden is all but useless, because if people can't find you, they're going to keep looking. Rather, the solution to his endless conundrum of how to hide away from the universe is to either make yourself not worth looking for, or to make it so that people don't want to find you.
- Carmen Sandiego: Chase maps out all the information A.C.M.E. and Interpol have on V.I.L.E. and realizes that only one location has no import or export records, which for a supposed import/export company, is pretty damning. He arrives just after the faculty has decided to torch the place and move on, so he winds up convinced he didn't find anything at all.
- The Deputy Dawg Show: "Diamonds In The Rough" has Deputy Dawg tasked with bringing in a diamond smuggler and his contraband. A golfer seems to be way off course as his ball ricochets in DD's office ("I slice badly"). Thanks to Vincent Van Gopher, Deputy Dawg reasons that the golfer is the smuggler and the diamonds are in the ball. When the golfer is subdued and brought in, the sheriff rails at DD because he said they had to have evidence. Deputy Dawg does: he swallowed the ball from an errant shot and it showed in an x-ray at the doctor's office.
- In the Justice League episode "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 Mad Scientist, not a god, the Law of Conservation is still in effect, and therefore Superman couldn't have just been destroyed. His conclusion; it teleported him somewhere. He's right - Supes was shunted forward in time, but the show doesn't make it clear whether or not Batman is simply in denial.
- In Steven Universe, Blue Zircon notices something wrong with the story of Pink Diamond's assassination - the assassin (Rose Quartz) supposedly approached her at her palanquin, took her by surprise, and killed her. So why wasn't Pink's retinue doing anything to stop her? Rose Quartz was immediately recognizable; she was the only active one of her kind. And nobody noticed she was there? Pink's Praetorian Guard didn't try to fight Rose? Her Sapphires didn't see it coming? Her Pearl (who would have been expected to always be by her side) never warned her of the danger? Blue Zircon then concludes that what actually happened was a conspiracy by the only Gems with the authority to order all others away, and who Pink Diamond would trust if they asked her to step out of the palanquin... the Diamonds themselves. This gets her poofed. But she was right. A Diamond was involved - Pink Diamond, conspiring with her Pearl to fake her own death. Rose was never spotted because "Rose" was actually her Pearl shapeshifted, the Sapphires saw nothing because they weren't looking for their leader plotting against herself, and her Pearl said nothing because she was in on it.
- One U.S. Acres cartoon (from Garfield and Friends) 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.
- The Bielefeld conspiracy meme parodies conspiracy theories 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 nonote it is concluded that Bielefeld doesn't exist. People who answer "Yes" to the questions 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.
- Forensic Accounting can sometimes function like this. On one occasion in the UK the police got a crucial break in a money-laundering case when it was noticed that the owner of a fast food restaurant wasn't buying enough paper napkins to meet their supposed demand.
- In the mid-2000s, the Oakland Raiders were concerned that quarterback JaMarcus Russell wasn't studying game film and plays as he was instructed to. One day, the coaches sent him home with some tapes and told him to report back to them the next day. When the coaches asked Russell what he studied on the tapes, he told them he studied the blitz packages. The coaches then revealed the tapes they gave him were blank.
- During the Manhattan Project, Soviet nuclear scientists noticed the lack of American papers on nuclear fission in academic journals, which indicated to them that the Americans were censoring them to secretly develop a nuclear bomb, and the USSR started their own nuclear project soon after.note
- Though this was Right for the Wrong Reasons, as the dearth of nuclear fission papers was the result of American scientists agreeing to not publish any papers that might give Nazi Germany the bomb.