I Never Said It Was Poison in live-action TV.
- Played for laughs on 30 Rock:Kenneth: I'm afraid I have some bad news.
Jenna: [eerily calm throughout] Jenny McCarthy died? But who could have been slowly poisoning her? Was she poisoned? I have no way of knowing, because I'm just hearing about it.
- Agatha Raisin: In "Agatha Raisin and the Curious Curate", the killer gives themself away when they mention what a close call James had had. Agatha remarks that no one knew James had been present at the murder, not even the police, and that the only person who could have known was the murderer.
- Agents of S.H.I.E.L.D.: In "Turn, Turn, Turn", Garrett accidentally outs himself as The Clairvoyant when, in an attempt to convince the team to kill the loyal agent they've mistaken as the Clairvoyant, he lists all of the Clairvoyant's crimes... including something Coulson learned from Raina that he never told anyone else, meaning there is no logical way that Garrett could know it. You can see the moment that he realizes what this means.
- Parodied in Angie Tribeca:Angie Tribeca: One last question. Any idea how your cufflink was found inside an illegal ferret?
Mr Frontbutt: Well, I travel all over the world. It may have fallen when I was in the mountains. You know, these Himalayan soft bellies, they'll eat anything.
Angie Tribeca: I didn't say it was a Himalayan soft belly.
Mr Frontbutt: Well, you didn't say it wasn't.
Angie Tribeca: Damn it, he's good.
- In an episode of Becker, Dr Becker is accused of being racist after a journalist construes angry comments he made about people he knows and confronts the journalist on a radio station and clears himself by pointing out he was angry on those people not because of their race but the things they did which annoy him (eg. Disliking rap music being played in public because it's too loud, not liking his Asian taxi driver because he crashed his car before). But when the journalist talks about Becker's Puerto Rican neighbor, Becker asks how the journalist knew his neighbor's race when Becker never mentioned it. It is then when Becker figures out that the journalist was the real racist as he was using Becker's comments to hide his own racist stereotyping.
- In an episode of Blindspot, a New York cop inadvertently reveals to Mayfair that he's in on a blackmail racket when he mentions one of the victims, a closeted gay football player, whom he would only have known about had Mayfair told him.
- Happens in the Bones episode "Mayhem on a Cross". Bones and Booth are interrogating a suspect, and tell him that another person has confessed to the murder. The suspect scoffs, saying that the confessor was not a real man, and it would take a real man to strangle someone with barbed wire. Of course, no-one had told him how the killing was done.
- Bosch: The season 3 finale has a variant of this where it concerns the investigating cop, not the suspect. While Jerry Edgar is recuperating from being shot, he watches the video of Rudy Tafero's confession to the murder of Edward Gunn, and notices that Bosch knew the Tafero brothers drove a Cadillac to the murder without Rudy saying so, and the car isn't visible in the video footage (from Bosch's unauthorized surveillance cameras) of the Taferos entering Gunn's apartment. This leads Edgar to realize that Bosch witnessed the murder and didn't intervene.
- An unusual variant in Breaking Bad, not connected to crime. Walt's old business associate Elliot Schwartz offers him a job. Walt refuses, citing personal problems, and Elliot assures him that they can sort those problems out, as the job comes with a great health insurance. Since Walt didn't elaborate that the problems are health-related, he deduces what happened: his wife told Elliot about his recent cancer behind his back, and the job offer is basically dressed-up charity, something Walt despises and would've never accepted even if he didn't hold a huge grudge against Elliot.
- In the Broad City episode "Kirk Steele", Abbi and Ilana discover that Abbi's boss Trey once starred in a porn video called "Kirk Steele: A Man on a Mission, A Cum Mission". Planning to blackmail him, Abbi addresses him as "Kirk" at work the next day. Trey takes her aside and says, "Abbi, when you said 'Kirk Steele: A Man on a Mission, A Cum Mission', what did you mean?" Abbi replies, "Well, I just said 'Kirk', but you have now confirmed that you are a porn star."
- Buffy the Vampire Slayer
- In "I Robot, You Jane", Willow realizes that Malcolm, a person she is talking to on the internet, is not who he claims to be after he mentions that Buffy burned her old school down, information that Willow hadn't actually told Malcolm before.
- Towards the end of season four, Spike and Adam cause Buffy to fight with her friends, then realize she needs Willow's help for their plan to succeed. Spike gives away his involvement by encouraging Buffy to make up with Willow, when she of course hadn't mentioned the fight.
- One episode of Cadfael has the titular monk use this to determine a suspect's innocence when he tells the man that his father was "cut down". The man denies ever drawing a blade against him, which provides one of the two pieces of evidence that Cadfael needs. The other is when he hands the fellow some monkshood oil as a refreshing drink to see if the man will recognize it; when he starts to raise it, Cadfael snatches it away and says that he's just proved himself innocent to the crime of poisoning his father.
- In an episode of Call the Midwife, a baby wrapped in a nightdress is rescued from a bin, and is taken into care. A newspaper article is published about the child, and later a woman comes in with a present for the child. The midwife on duty reports this woman to the police, suspecting her to be the mother, since she commented on how the child was found wrapped in a nightdress even though that detail was not mentioned in the article.
- This is how Castle and Beckett identify Beckett's mother's killer. A man suspected of hiring the same contract killer is trying to cut a deal for full immunity from all charges, by insisting it's the only way she'll ever find the guy who killed her mother. Beckett later realizes that she never told the suspect which of her parents was murdered, and that he is the contract killer.
- On another episode, Castle and Beckett interview the brother of a serial killer who had previously been convicted at a trial whose key witnesses are now being murdered one by one. He points out that he's been locked in an insane asylum since the trial, so who could he have sent to kill the two witnesses? Castle points out they only mentioned "one" murder. (Turns out he totally didn't do it, he was just having someone follow the murders and try to stop the real killer, precisely because he knew he would look guilty.)
- It is also how they catch the serial killer in the first episode. When they ask him where he was during his sister's murder, he immediately provides an alibi for all three murders. As Beckett points out, knowing where he was when his sister died is understandable, but the other two were strangers to him.
- The Closer: Brenda's questioning of a suspect rattles him to the point of mentioning a detail of the murder he shouldn't have known in "A Family Affair".
- Subverted in an episode of Cold Case. A suspect in a double homicide states that he'd "never use a bullet on a black man", which raises suspicion because the detectives never told him how the victims were killed, but when Jeffries calls him on it, he insists it was just a figure of speech. Jeffries is skeptical, but it turns out the suspect was telling the truth and really didn't have anything to do with the murders.
- Frequently used in Columbo.
- In "A Deadly State of Mind", Columbo finds a witness to a crime — a blind man. So they bring their suspect, Dr. Collier, in, and have a guy in shades walk in, sit down, and identify Dr. Collier as the man who nearly ran into him while driving away from the Donner house on the day of the murder. Dr. Collier says his his medical training tells him the man is blind, and hands him a newspaper... which he reads perfectly. Columbo reveals it's actually the blind man's similar-looking brother, and there was no way Dr. Collier should've thought he was blind. Unless, of course, he saw the real blind man while fleeing the scene of the crime.
- In "Negative Reaction", Paul Galesko incriminates himself by grabbing the incriminating camera used to take pictures of his wife. The mistake is that he grabs the correct one right away, instead of mistakenly grabbing a different one from a shelf full of cameras.
- In "Butterfly with Shades of Gray", there is a subversion, since Fielding Chase mentions that the victim was shot in the back. Most viewers assume that Chase only knows this because he is the shooter, but Chase does give a reasonable explanation to make it seem like he didn't commit the crime (since he made it seem like he was on the phone with the victim when he was killed), by stating that the victim would have told him over the phone that someone was aiming a gun at him, but since he didn't, he obviously was turned away from the shooter.
- Subverted in Community in "Advanced Documentary Filmmaking". Chang, apparently suffering from "Changnesia" and calling himself Kevin, mentions Jeff being a lawyer. When Jeff points out that he shouldn't know this, seemingly catching him out, he recites a conversation Jeff and Shirley had earlier, wherein she mentioned him being a lawyer.Chang: Jeff, thank you. When the Dean told me you were going to help me, I couldn't believe it. A cool, smart lawyer like yourself, reaching out to a little nobody like me.
Jeff: [smirking] I never told you I was a lawyer.
[everyone exchanges concerned glances and looks at Chang suspiciously]
Chang: No, you didn't. Shirley said it, remember?
- The Coroner: In "Perfectly Formed", Lee Milar refers to dead baby as 'him', prompting Jane to ask how they knew it was a boy.
- A non-criminal example from The Cosby Show: Claire discovers her favorite mug has been damaged, poorly glued back together, and replaced. Heathcliff expresses his shock that one of the children would put it back in the cupboard. Claire never said it had been put back in the cupboard. Rather than quickly covering by stating that that's naturally where a mug would be, Cliff further steps in it by saying "way back in the cupboard".
- In an episode of Covert Affairs, Annie is looking for a mole in a training academy, and realizes that one of the trainees was out buying illegitimate booze the night of a leak. She asked why that night, he said he knew he could sneak out because everyone would be busy dealing with another trainee who'd just been cut from the program. None of the other trainees knew she'd been cut until the next morning. (Circumstantial, except when she mentioned that, he attacked her.)
- Standard operating procedure in Criminal Minds as well.
- Best use was probably "The Fox", where the killer, profiled as probably having OCD, has a minor Freak Out during questioning when he notices the pictures of his victims are out of order (which was done on purpose by the investigators).
- The episode "A Real Rain" has the BAU chasing down a vigilante, killing criminals by stabbing them through the head. When they are questioning an impostor, Gideon asks him: "Is that why you stabbed him in the groin?", and realizes that he was lying by his affirmation.
- In yet another episode, their usual plan of withholding things from the media was thwarted by a leak and they had to find it quickly.
- Maeve's stalker is ID'ed this way (too late). Reid and Hotchner are interrogating the prime suspect when Reid gets too emotional and Hotch sends him out. The suspect's girlfriend chases Reid down to ask him a question and addresses him as "Doctor." It isn't until later that he realizes he was never introduced, so she should have addressed him as "Agent."
- In one case, Brass (after the fact) realizes that he should've been suspicious of the husband of a woman drowned in the bathtub from the beginning when he remembers that, while she is being carted away by the EMTs and it's not yet clear whether she is going to make it or not, the husband says: "I loved my wife." Whoops!
- In the B Story of "Slaves of Las Vegas", Warrick and Sara ask a suspect in a robbery to show them his car. He does so and then says "See! It's not even the same model!" Sara then points out that they hadn't told him what model they were looking for.
- In the episode "Missing Present Mystery" of Dani's House Dani tries to work out who took Alex's football shirt and anniversary present from her wardrobe. Her friend's sister Maisy convinces Dani that she didn't steal it because the number on the shirt (14) is her unlucky number. It takes Dani a while but eventually she realises the flaw in this reasoning.Dani: I never showed you the number on the back of the shirt.
- In Day Break, Hopper often reveals that he knows more than he should due to his expanding knowledge from previous time loops which gets him into tricky situations.
- In episode 10, Hopper wants Battle to look into all murder cases done execution style. When Spyvak hears this, he notes that this further incriminated him since Garza was killed that way and the information was not released to the public. Battle is not impressed by this detail and sticks with Hopper.
- In episode 11, Hopper tells Rita in the morning that he did not kill Garza though he should not have known about the murder at this point which makes Rita suspicious.
- Debra Morgan from Dexter realizes who really shot her and Lundy when the perpetrator asks her what it was like to watch the life go out of the eyes of the man she loved. This was far from common knowledge even in the station. She does consider that the person could have figured it out or been told by another cop, and investigates accordingly, but eventually concedes that there is no other explanation.
- Doctor Who:
- "Marco Polo": Tegana mentions the location of a passageway in a cave he claims never to have visited.
- "The Keys of Marinus": Susan is kidnapped and her captor forces her to speak to Barbara over a futuristic alien phone. Later, the kidnapper accidentally lets it slip in conversation that she is aware they have spoken to Susan, even though it was not mentioned. This allows Barbara to realize her guilt.
- "The Time Meddler": The Meddling Monk (who is holding the Doctor prisoner) claims that he hasn't seen the Doctor but gives himself away by knowing what the Doctor looks like without Steven having told him. This is a subversion: The Monk wanted to lure Steven and Vicki into his base, and made the "mistake" on purpose.
- "The Daleks' Master Plan": The Doctor realizes that Daxtar is a traitor because he knows that the Daleks' doomsday device requires a core of taranium even though the Doctor never mentioned it.
- "Remembrance of the Daleks": The Doctor and Ace find out that Mike Smith is working for the Daleks when he says "I don't get it. They've got the Hand of Omega. Why don't they just leave?"
- In Downton Abbey, Mary mentions to Rosamund that Edith has taken a strong interest in the Drewes' foster child. Rosamund (who suspects that Edith has recovered her illegitimate daughter; which Mary does not know about) tries to ask more about Edith's relationship with the little girl. Mary, who didn't mention the child's gender, asks how Rosamund could have known it's a girl.
- Father Brown: Father Brown identifies the killer in "The Eve of St John" when he realises that they knew the eye colour of the victim despite claiming never to have met them.
- In "Bushwhacked", an Alliance official tries to use this one on Mal, telling him they're looking for a brother and sister without mentioning the two are adults. Without batting an eye, Mal pretends to assume he's talking about children.Harken: Alliance property, too. You could lose your ship, Captain. But that's a wrist slap compared to the penalty for harboring fugitives. A brother and sister. When I search this vessel, I won't find them, will I?
Mal: No children on this boat.
Harken: I didn't say "children". Siblings. Adult siblings.
Mal: I misunderstood.
- Also averted in "The Train Job", where Mal very carefully asks the sheriff (paraphrased) "Why are we being held up? Was someone murdered on the train?", while knowing full well that the real reason was because people had just noticed that the cargo he had stolen was missing.
- In "Trash", Mal meets an old friend Monty's new bride, an old enemy. They pull guns on each other and fight. After Monty separates them, Mal explains their mutual history to all present, and then:"Bridget": You're a liar, Malcolm Reynolds!
Monty: ...now I ain't never got to tellin' ya his name.
- Thereby proving, at the least, that she and Mal weren't strangers, as she had said. Had she not made that mistake, she still would have had to explain why their first reaction upon seeing each other was to pull a gun on each other.
- In "Bushwhacked", an Alliance official tries to use this one on Mal, telling him they're looking for a brother and sister without mentioning the two are adults. Without batting an eye, Mal pretends to assume he's talking about children.
- The Flash (2014): In the episode "So Long and Goodnight", Joe confronts Carver over setting Ragdoll on him, and Carver asks if he's actually being accused of hiring a contortionist hitman to hide in a box. Joe points out he never mentioned a box, but Carver just laughs and says he got him there, but there's still no way to prove it.
- In one episode of Flashpoint, when trying to find a kidnapped girl and her mother, the team goes to see the estranged grandmother who was visiting. She said she didn't know she even had a granddaughter and yet knew the granddaughter's name, alerting the team that she knew more than she claimed.
- In one episode, the Victim of the Week was pretending to be a British noble to con a wealthy family. When Jo and Henry interview the victim's fiancée's father, he mentions Dwight (the victim) having been a con man, which they never told him. He claims his daughter told him, but the police didn't tell her, either (they only told her Dwight's real identity). The father then admits that Dwight came to him and confessed.
- In "Diamonds are Forever", Detective Dunn gives himself away as an accomplice in the crime Jo is investigating when he mentions that her house is in Washington Heights. As her husband was a prosecutor and therefore suffered the occupational hazard of having a lot of people want him dead, their address was kept secret even from the police. She never told him where she lives, so the only way he could know is if he'd been there before. He was the one who murdered the Victim of the Week, who was trying to knock on Jo's door at the time.
- In the Future Cop episode "The Mad Mad Bomber", Cleaver breaks Haven out of the Synthetronics lab where he's about to be dismantled. Later, Captain Skaggs and Dr. Tingley show up at his apartment to ask where Haven might be. Cleaver asks, "Are you accusing me of taking him?" Skaggs replies, "Who said anything about taking him?" Cleaver protests, "Well, she said it was missing! Didn't you say that, ma'am?"
- Played for laughs in The Games: after taking an Albanian delegation sightseeing and setting fire to one of the members of the delegation's wigs, Gina confesses this to Bryan, who tells it to John... who tells it to a gossip columnist. Gina arrives at his house on the weekend and says she'll lynch Bryan for leaking the story, as she only told him, and John plays along before mentioning the name of the columnist. Gina immediately says 'I never said it was in Manny's column. How did you know it was Manny's column, John?' and he stammers until she gets up and walks out.
- An episode of General Hospital had the cops interrogating a man found driving a missing woman's stolen car (He had carjacked her and left her on the side of the road, but had otherwise left her unharmed). The man tries to claim that he found the car abandoned and denies having ever seen the woman, but when the cops accuse him of foul play, he angrily declares, "I would never hurt a pregnant lady!" The cops had never told him that that the woman was pregnant.
- On The Gifted, Erg is with his lover, Pam, who tells him the rest of their mutant group was split up. Erg is eager to go back and help Evangeline with Pam insisting they have to just run. She tells him that "once she gets across to Flint, she'll be okay." Erg realizes he never tells anyone where the "mutant crossings" happen and that Pam has been flipped by Sentinel Services.
- In "The Case of the Libertine Belle," an episode of The Golden Girls, Blanche brings the staff of the museum where she works, along with the girls, to a murder mystery weekend. Things take a turn for the serious when Blanche's boss Kendall is found dead in her room when he and Blanche had the only keys, and it appears to not be a fake crime. The next morning, Blanche's work rival Posey angrily claims that Blanche did it out of jealousy, describing how her dress was "flung over the bed" when Kendall arrived in the room. Dorothy then realizes that the only people who saw the room after the murder were the girls themselves and the police...so how did Posey know about the dress on the bed? The cops charge Posey with the crime—and that's when Kendall comes downstairs, because his supposed death was actually All Part of the Show.
- A major turn on Grand Hotel is a flashback to Beatriz suspecting husband Santiago is cheating on her with best friend Gigi. She rants about it to hotel manager Helen, bringing up how Santiago had confessed having a one-night stand with another woman years ago. Helen assures Beatriz is nothing is happening with Santiago and Gigi and "you can't get worked up over something that happened fifteen years ago." Beatriz instantly snaps she never said when Santiago had that affair and realizes Helen was the other woman. Beatriz then quickly does the math and asks Helen how old her son Jason is...
- The Hardy Boys/Nancy Drew Mysteries: In "The Mystery of the Hollywood Phantom", Joe deduces that one of the suspects is behind the kidnappings partly because when the suspect heard that a room had been "wrecked" and that blood was found on the scene, he said that the blood was probably from the broken glass, even though he'd never been told there was broken glass. When the brothers confront him with the information, he protests, "When you tell me that a room has been wrecked, naturally I assume there might be broken glass lying around. Hardly conclusive evidence."
- An episode of the new Hawaii Five-0 has the kidnapper of some college students ask for a woman who'd hid from them during the initial kidnapping, by name, be the one to deliver the money. She shows up to do so... and breaks into a smile, revealing that she was working with the kidnappers all along. They open up the bag only to find it packed with newspaper instead of money and the police burst in to arrest them all. When asked later how he knew she was in on it, Steve points out her name had never been published in the media to protect her identity.
- Home and Away:
- A guest character accidentally incriminates herself by identifying a fishing knife as a murder weapon. The police just called it a knife. (It turns out that she was just a witness to a killing that was actually in self defense.)
- A later episode had Xavier end up taking heat for April's crime when he said that he was looking up the chemicals she stole. Gina figured it out because she hadn't specified what the stolen chemicals were.
- In Homeland, when Carrie and Brody are having a romantic getaway at her family's cabin, she tells him that unfortunately she doesn't have any of his favorite tea, Yorkshire Gold. Unfortunately for Carrie, that is, seeing as Brody never told her what his favorite tea was, and he realizes instantly that she must have been spying on him.
- Subverted on Homicide: Life on the Street: In "Bad Medicine", Detective Lewis tells Villain with Good Publicity Luther Mahoney that a recently deceased thug obviously committed suicide. Mahoney scoffs, pointing out that the victim was shot in the back of the head and the gun was left on the table next to him. Lewis gleefully pounces, proclaiming that neither piece of information was released to the public and placing Mahoney under arrest. In the end, though, the state's attorney figures that there are any number of ways Mahoney could have learned it, too many to be beyond reasonable doubt.
- Hotel Beau Séjour. Invoked by Charlie. When he falsely confesses to the murders, he includes details that were not released to the public so the police would believe him. Unfortunately, the police didn't count on him stealing the notebook of a ghost who was spying on the investigation.
- Inverted in Human Target: Chance suspects the cops escorting his client of being the ones trying to kill her contact. They're too clever to let this slip, so he openly mentions an unknown fact about the meeting place (that it was on a bridge) and uses their lack of response to this "new" information to confirm his suspicions.
- In the iCarly special iPsycho, Gibby, coming to rescue his friends from Nora, an Ax-Crazy Fangirl who kidnapped them, he asks her if she's holding his friends here. She replies there's no one in her basement, confirming Gibby's hunch that they'd been kidnapped, as he then points out by saying that he never mentioned her basement.
- In The InBESTigators, Maudie uses this on a couple of suspects to get them to unintentionally confess.Maudie: Hi, Im Maudie. Im the one who answered Ezras phone on Thursday.Luka: Friday.
- Averted in "The Case of the Robot Robbery". While the Inbestigators never mention that Duncan's costume was a robot costume when interrogating his classmate, it turns out that Duncan bragged about what his costume was going to be to his class so they have to keep investigating.
- JAG: Played straight in "Washington Holiday", when the team were witnessing a failed assassination attempt on the Romanian royals. Told that the would-be assassin had named him as being behind the plot, the Evil Chancellor protested that it was ridiculous to accept the word of a woman who had been subjected to lengthy police questioning. Of course, nobody had mentioned that the assassin was female...Minister Kepish: Your Majesty, how can you possibly believe the lies of a woman tortured by the Belgian police?
King Josip: How did you know the assassin was a woman, minister? They didn't even tell me that until an hour ago.
- Done in the Jake 2.0 episode "Arms and the Girl", when Jake figures out that Theresa is really the bad guy thanks to her knowing how many times the fake version of her father was shot before the NSA does.
- Jake and the Fatman: In "It Had to Be You", McCabe tricks a serial rapist into accusing three women of conspiring against him and saying that he raped them. McCabe points out that the victims' identities were never released to the media, so the only way he could know they had been raped is if he was the rapist.
- Jonathan Creek:
- In "The Problem at Gallows Gate (Part 2)", the murder victim's housemate makes a snide comment about Maddy being burgled. As Maddy points out after revealing her to be the killer, she never told her about her burglary. The only way she could have known about it was her hearing Maddy mention it on the night of the murder while she and Jonathan were trying to enter the house.
- Played with in "Satan's Chimney", when Jonathan's new investigative partner, Carla Borrego, comes on stage to tell Alan Kalanak "It's Vivian" (referring to his ex-wife, Vivian Brodie, the murder victim of this episode) while holding a phone. As Jonathan later notes, anyone else would assume that Carla meant that it was Vivian on the phone, but Kalanak instantly asks what has happened to Vivian, planting the first seeds in Jonathan's mind that Kalanak was involved in her death.
- Justified: When the marshals yank a pair of suspects out of a car in "Save My Love", one of them immediately says she doesn't know anything about a bomb threat and doesn't even have a cell phone. Gutterson's response is that no one mentioned a bomb threat.
- In the various Law & Order shows, the detectives will often hold back certain details of the crime from the press, so they can test the veracity of any account from a suspect or witness. As many times as it's used to trip up the guilty, it will also expose someone attempting to confess falsely. For instance, a father taking the rap for his son's crime not knowing what the victim was tied up with.
- The inverted version is also used in serial killer cases so that the cops have a way to distinguish copycat cases from those actually committed by the killer. Unfortunately, this can fail, as it does several times across the franchise, if the copycat killer is a member of law enforcement or otherwise close to the case and therefore has access to details not released to the public.
- Avoided in one Law & Order episode when McCoy decides to go through with a generous plea deal with a suspect that covered "miscellaneous crimes" after the police told him the suspect's partner was dead. He exploited a loophole that allowed him to charge the defendant with crimes the DA didn't know about before making the plea; since the police never said the partner was murdered, he had no way of knowing his death was a crime.
- Detective Goren in Law & Order: Criminal Intent was a master of getting suspects to incriminate themselves. In one episode ADA Ronald Carver tells Goren to try one of his "tricks" to make the suspect reveal incriminating information.
- A variation comes up in another episode of Criminal Intent, when a witness in a murder trial reveals a detail of this type on the stand. They had already established that the witness, who had been the initial suspect in the case, couldn't have done it (he didn't know how to get to the place where the victim's body had been dumped), but they also know the defendant wouldn't have told him that detail, so they realize that there had to be someone else who had seen the victim the night she died.
- Explicitly lampshaded in Law & Order: LA when the prosecutor asks the defendant, a Secret Service agent, if based on his long career and investigations that he'd agree that a suspect displaying knowledge of the crime was probably guilty. Defendant says yes. Prosecutor presents the text messages (sent from a smartphone they'd found concealed in the defendant's cell) to the victims' husband/father revealing information that only someone present in the house just before the attack would have known.
- Subverted in an episode of Law & Order: Special Victims Unit. After a lengthy interrogation, Olivia catches a suspect mentioning a scarf that only the rapist would know about. The man confesses, is convicted and sent to jail. Eight years later, she discovers that there had been a mistake in the evidence report, and the suspect's confession had matched the report, not the reality. Olivia realizes that someone, quite possibly her, must have inadvertantly let the detail slip without realizing it. She essentially browbeat a tired and confused man into confessing to something he never did.
- The League of Gentlemen, end of first episode in the Local Shop: just as a policeman investigating a missing person is about to leave the shop and go on his way, Tubbs blurts out "We didn't burn him!"
- On Lethal Weapon (2016), DA Erica is talking to a man who claims he was set up for a murder by a corporation. She's with him going over the evidence and how he knows more of the company's dark deeds. She mentions a murder and the man notes how the victim was killed by garden shears... which was a detail that no one but the killer could have known.
- In an episode of Limitless, a CEO denies having had an affair with an intern, but the FBI didn't know the woman's identity or that she was an intern.
- Longmire: In "Dogs, Horses and Indians", the killer mentions that the Victim of the Week was murdered on the reservation; a fact that only the killer could have known.
- Played straight in the MacGyver episode "Hell Week", in which MacGyver catches a cheating contestant in a physics competition. The object of the competition is to create a barricade to a room with some unorthodox way to "unlock" the door. The good guy creates an optical illusion using a periscope to make the door look locked when it's really unlocked and vice versa. The villain eavesdrops on a conversation between his rival and a friend, and thus "wins" the competition...but he never actually looks into the room to see the periscope. Naturally, our hero notices this and...Jeffrey (the cheater): You all saw it. The door was opened; it was an optical illusion. He used that periscope.
MacGyver: That's right, he did. That's exactly what he did. But you had no way of knowing that. Jeffrey, you opened the door, but you never looked inside. You never saw a periscopeat least, not this afternoon.
- On The Magicians, Quentin wakes up in a mental institution and told all his experience with the magic school were a delusion. Other characters appear as patients to explain them in his "dream" but Quentin is convinced he's trapped in an illusion. When his friend, Julia shows up, Quentin creates magic which she appears not to see. But one slip of the tongue makes Quentin realize that Julia actually helped trap him here.Julia: I wish I could have seen the fireworks.
Quentin: How did you know they were fireworks?
- The Mentalist:
- In the episode "Red Badge", Lisbon is framed for murder. Jane suspects he knows who the real culprit is, but lacks evidence, so he arranges to put Lisbon and the suspect in the room together. The real killer's goal is to convince Lisbon she was the culprit and blocked out the memory, so she lets him prompt her with details about the crime until he slips up.Dr. Carmen: The reek of the garbage, the filthy alley walls, the faded cross there. God might have mercy on William McTeer, but you sure as hell wouldn't. He deserved to die, but you're still a good person, Teresa. You can get through this.
Dr. Carmen: Uh, what?
Lisbon: The cross, Roy. How did you know about the cross? It was inside the door. Only the killer saw.
Dr. Carmen: Well, Teresa, you told me about the crime scene.
Lisbon: No, I didn't.
- In a later episode, Jane uses this to catch the suspect in the murder of a young woman. His suspect has a known habit of correcting people, so Jane discusses the case in front of him and deliberately gets a detail wrong. The suspect reflexively corrects him, thereby giving away that he knows more about the murder than he's saying.
- In the episode "Red Badge", Lisbon is framed for murder. Jane suspects he knows who the real culprit is, but lacks evidence, so he arranges to put Lisbon and the suspect in the room together. The real killer's goal is to convince Lisbon she was the culprit and blocked out the memory, so she lets him prompt her with details about the crime until he slips up.
- In the Miami Vice episode "Everybody's in Showbiz", Crockett is questioning a suspect about a stolen briefcase, without mentioning that it was stolen from a limousine. The suspect says that he "ain't been in no limo," to which Crockett replies, "What limo? Did I say limo?"
- In a later episode "Fruit of the Poison Tree", the episode's villain of the week attempts to kill Gina who's working undercover as his girlfriend with a c4 bomb which instead kills a 12 year old boy. Later while discussing it with his lawyer, a junior attorney asks how they can defend a child killer to which the lawyer mentions that "A lot of criminals would want to hit a cop with C4" to which the attorney asks "How did you know it was c4?"
- In one episode, the Captain shows a gun that had been used to murder the victim to the victim's friend. The friend points out the cracked handle on the gun and says that the victim was bludgeoned to death (which he was). Near the end, the Captain realizes that anybody who didn't know would assume that the victim had been shot, not beaten, and arrests him as he's about to kill Monk.
- When an infant in foster care is found handling a kidnap victim's severed pinky in the park, Monk deduces at the very end that it was his foster parents, one of whom was told the child found a finger but replied back that he found a pinky.
- In another episode, a man suspected of killing his wife points out that the police already have a suspect, calling him a "chain-snatching, dope-sniffing punk." Leland points out that the police hadn't revealed that the kid in question had stolen a chain to the public, thus only someone present when it happened could know about it. (On his way back from killing his wife, he broke his tail light. If he got pulled over for it, it would break his alibi, so he had to get it fixed. While he was there, he witnessed the kid robbing the auto shop and realized he was on camera, so he killed the shop clerk and took the camera footage.)
- There was a hilarious subversion on the episode where Monk's medication interferes with his deductive talents. Monk attempts to nail the killer with "guilty knowledge":Monk: How did you know she was wearing a bathrobe? No one said anything about a bathrobe!
Killer: You did! Two minutes ago!
- In yet another case, Monk is called in to help along the investigation of what appears to be a woman's suicide. When the woman's co-workers are told about it, one of them immediately asks about the suicide note. Later, Monk points out that suicide notes aren't especially common, and the guy didn't ask if there was a notehe knew there was a note. Pay no attention to the fact that most people don't know about the frequency of suicide notes.
- Monk identifies the culprit in one episode when he realizes he knew the victim's widow - the two were lovers and had colluded in the murder. Monk had seen the two speak to each other as if they'd never met while she mourned her husband in church, but the man gave himself away by referring to her as a widow even though she hadn't told him it was her husband she'd lost.
- Features in a roundabout way in Murder Rooms, when Doyle identifies the true killer in "The White Knight Stratagem" when he reads a description the man wrote of a complex chess game; the account was far too detailed for the unobservant idiot the man had been presenting himself as to Doyle and Bell, which prompted them to analyse his actions up to that point from a new perspective and realise that he was the guilty party.
- Used frequently in Murder, She Wrote.
- In one episode, the suspect is asked to the police station and, while waiting outside the detective's office, is passed by the office security guard (not in uniform). He's then called in, where Jessica tells him her theory. His murder plan involved working late every night so the guard wouldn't know what he looked like, then re-entering the office building disguised as a delivery guy.Suspect: Is that what this is about? You drag me here to see if the guard recognises me? Well, it didn't work! He didn't know me from Adam!
Jessica: What makes you think that man was the security guard?
- One episode has Jessica Fletcher tell a group of suspects the murder weapon was found and the killer was identified because he later referred to it as a pizza cutter.
- An early episode had a murderer identify the as-yet-unspecified color of a shoe found at the scene of the crime. Arguably a downplayed example here, though, because Jessica had already worked out the culprit; the slip-up simply allowed Jessica to set up an Accidental Public Confession.
- Yet another episode had a woman insist that she knew nothing about the murder of a private investigator who had been investigating her. Jessica had only said that the PI was dead, not that he was murdered. Interestingly, while her slip did reveal a connection to the PI, she was not involved in the murder.
- Jessica relates how a woman was poisoned via the special cigarettes someone slipped her.Killer: You're balmy. My aunt only smoked British cigarettes, nor Turkish.
Jessica: And how did you know the cigarettes were Turkish? We only got the lab report back an hour ago.
- Another episode had this happen with an actual poisoning, though in this case the culprit (a newspaperman) was exposed because he pushed a front-page story that identified the effect of the poison (a cerebral hemorrhage) as the cause of death, even though that effect was not revealed until an hour after the paper was published.
- Another downplayed episode occurred when a man who murdered his wife had attempted to frame an unknown art thief, only for the victim's father to find the scene and rearrange it to frame him: one of the many clues that Jessica cites when exposing him is his knowledge of a tool supposedly used by the 'thief'. He also protests his innocence by pointing out a broken clock that showed a time of death for which he had an alabi -- except that the clock had been taken as evidence before he should have known about it. Again, those were just two clues that Jessica used to work out the case, rather than the sole cause of incrimination.
- In one episode, the suspect is asked to the police station and, while waiting outside the detective's office, is passed by the office security guard (not in uniform). He's then called in, where Jessica tells him her theory. His murder plan involved working late every night so the guard wouldn't know what he looked like, then re-entering the office building disguised as a delivery guy.
- Murdoch Mysteries: In "The Murdoch Appreciation Society", the real murderer is a bit too eager to point toward the man he's trying to frame (his ex-professor who fired him from university), and tells Detective Murdoch that they have to stop him before he strangles another person. Murdoch is prompt to note that he never revealed the victim was strangled.
- One of the several clues that a midshipman's training sergeant had been guilty of his murder was that when Gibbs notified him of his (missing-presumed-deserted for several days) student's death, without mentioning that his death was murder, the sergeant's first question was 'Do you know who killed him?' note
- In a later episode, the suspect's wife assures Gibbs that her husband would never shoot a woman in the back. Of course, Gibbs hadn't mentioned to her or her husband how the victim had died.
- Used in season 3 when a lieutenant working in the Cryptology unit was found murdered. Her boss asks Gibbs about her having shot herself, and Gibbs says later that only two people know how the Lieutenant died... one of her coworkers (who he'd interrogated) and her murderer. He then turns to the boss and asks, "How did you know she shot herself?'
- An example from season 2: A woman with amnesia comments that "someone bashed that poor man's head in," when no one had told her how the man was killed. Unfortunately, by the time Kate realizes this, it's too late.
- In "Bikini Wax," De Nozzo has a surfer in interrogation and announces his DNA was a 99.98% match as a baby father for a dead Petty Officer, who was also a bikini model. He tells the guy that he left four messages for him, his girlfriend, watching from the observation room, says to Gibbs and company "He never left any messages." Gibbs counters with, "How do you know?" They later lift prints from the water glass they gave her while watching.
- In one episode of The Office (US), the Scranton branch has a surplus at the end of the year and splits into two camps trying to figure out how to spend it. Michael learns from the CFO that he can Take a Third Option by returning the surplus and get a 15% bonus. He then gives himself away by adding "dollars" to the sum when Oscar asks what 15% of 4300 (the surplus) is.
- On One Life to Live, a woman pretended to be a modeling scout in order to befriend a young co-ed and convince her to file a sexual harassment complaint against her professor (she wanted to get back at him for writing a tell-all book about her). When the scheme was discovered and everyone confronted the woman, she repeatedly and emphatically lied through her teeth about it and scornfully derided the girl's modeling aspirations—only no one had mentioned that this was how the two had met.
- A variation in Person of Interest had (ex-Army) Detective Carter interrogating several suspects to determine which was former military. All of them were, but were hiding it due to being mercenaries. During the interrogation, Carter demands one suspect's military service number, but uses an obscure term for it. When he angrily replies he never served in the military, she demands to know how he knew the term.
- Pie in the Sky: When Henry Crabbe is under suspicion of having been bribed by Hooperman to let him get away, the real culprit reveals himself by mentioning a message Hooperman sent to Crabbe that Crabbe hasn't told anybody about.
- In an episode of The Pretender, only the actual killer of a young girl knew what the victim looked like: There were no pictures in the news of the crime.
- On Prodigal Son, Malcolm is being questioned by a shrink over his actions on a case hunting a person named Andy kidnapped by a deprogrammer. The shrink decides Malcolm is unfit for duty and "someone else will have to find her." Smirking, Malcolm points out that at no point did he ever say Andy was a woman. This whole thing has been a scheme to expose the shrink as the deprogrammer.
- When the killer of the week is told that he was identified by a witness.Killer: Al Mooney is insane! Nobody will believe what he says.
Lassiter: Hang on a minute! I don't believe anyone said the witness' name. You're under arrest.
- An earlier example from Season 2, Episode 9 ("Bounty Hunters") when Shawn and Gus identify the killer:Juliet: Do you have an alibi?
Cole: I don't need an alibi, I'm not guilty.
Juliet: Oh, well, that's okay. 'Cause we can just look at the security cameras from the parking garage.
Cole: There were no cameras in that parking gara...
- Season Six has Henry talking with his old partner after solving a case involving a couple of dirty cops from back in his days on the force:Henry: I don't understand how they could do something like that.
Partner: Well, fifty thousand dollars was a lot of money back then. [cue "Eureka!" Moment when Henry realizes that he never told the partner how much the other cops were being paid, and eventual season finale when Henry is shot for uncovering the secret]
- Inverted with Shawn himself. The first episode has him get arrested because he gave information to the police, though he really wasn't involved in the crime, just observant enough to get the information from watching the news. He is forced to pretend to be a psychic, which for some reason is more believable to the police than the actual truth (though they do initially threaten to prosecute him if he's found to be lying).
- When the killer of the week is told that he was identified by a witness.
- In the Sanctuary episode "Folding Man", the body of a Rebellious Rebel Abnormal named Aaron is found stuffed in a washing machine. When the group the man belonged to captures Zimmerman, Zimmerman asks them what they're going to do about "what happened to Aaron". The killer mentions the washing machine in his answer, and Zimmerman points out that the killer has no innocent explanation for knowing about the washing machine. The group turns on the killer.
- Sherlock: In "The Abominable Bride", Holmes mentions the name Ricoletti to Sir Eustace, and Sir Eustace says that he has never heard of her. Holmes then observes that he never said that Ricoletti was a her.
- Subverted in the Shetland episode "Blue Lightning Part 1". When Perez tells Peter Latimer that Dr. Blake has been murdered, Latimer refers to her as Anna. Perez calls him out on this, pointing out that he could have been referring to Anna's husband, to which Latimer replies that he assumed Perez was talking about Anna because they were colleagues. It turns out Latimer is in fact innocent.
- The Shield:
- There was an episode that used this trope very subtly. They mention to a suspect that the victims' clothing was found. When the suspect mentions the burned clothing, the interrogator doesn't react at all, and if you're not watching very closely you won't even know why she has a contented look on her face after the interview. Unlike most instances of this trope, the detectives don't gloat to the suspect or do anything else to let the audience in on what's going on.
- During season 3, while the Money Train heist is being investigated, Vic lets slip the name of a club he shouldn't know about to Dutch (one of the best detectives in the station). Vic even has a tiny, private Oh, Crap! reaction right after letting it out.
- In the Shoestring episode "The Teddy Bears' Nightmare", Eddie tries to return a stolen handbag to its rightful owner. She tells him it can't be hers because she gave the handbag she bought to her mother, who would have told her if it was stolen. Eddie replies, "I didn't say it was stolen."
- In the failed pilot for Snavely, a Transatlantic Equivalent of Fawlty Towers, Henry Snavely (the Basil character) arrives in reception carrying a mountain goat's head that used to be hanging on the wall, and tells his wife "You'll never guess where I found it!" She replies "What made you look in the furnace?", then realises what she's said and winces.
- Square One TV:
- An unusual variation where a guilty person is trying to frame an innocent, but then gets details of the innocent man wrong. In the Mathnet segment "The Trial of George Frankly", George confesses to the bank robbery, and says how sorry he is to his wife and children. The real George Frankly has no kids, proving that this George is an impostor; he was really a criminal George arrested years ago, who was trying to frame him for a bank robbery in revenge.
- Another Mathnet example was "the Case of the Missing Air", involving a shock jock, Byle Dupe, suspected of robbing businesses who stopped sponsoring his radio show. While Dupe eventually is captured in the act, George Frankly and Kate Monday are convinced he's their man earlier on. Why? While questioning him on the robberies, Dupe claims to have been doing his radio show when the robberies took placeyet the time the robberies occurred were not made public.
- The most ridiculous use, however, would be "The Case of the Poconos Paradise". Main villain I.O. Privacy had a rather interesting scam going: She would use the mailing house she ran to offer free weekend getaways to certain people, and while they were gone, her goons would rob them blind. When Frankly and Tuesday begin to suspect her, she jumps through several hoops to pin the crime on their earlier suspect (the owner of the titular resort), most importantly sacrificing her goons by cooperating the police in a sting operation. She leaves immediately after she sees one get caught to complete her frame-up; and then she blows it at the last minute by giving the correct number of henchmen during The Summation, a detail the protagonists only learned after she left.
- In the Stargate SG-1 episode "Window of Opportunity", several planets, including Earth, are trapped in a "Groundhog Day" Loop, but only O'Neill and Teal'c are aware of what's happening. During one of the cycles, they arrive to the planet that has an Ancient device that causes the loop and meet an archaeologist O'Neill remembers from the first cycle. The man mentions Carter by name, causing O'Neill to notice that he didn't introduce her this time around, which means that the archaeologist is perfectly aware of the loop and is the one causing it.
- In the Starsky & Hutch episode "Texas Longhorns", the detectives are questioning a man about a Latino and a white man with tattoos accused of rape and murder. The man says, "I don't know any Puerto Rican or Anglo with tattoos!" Starsky replies, "I didn't say he was a Puerto Rican. Hutch didn't say he was a Puerto Rican. You said he was a Puerto Rican. I think you know the man."
- Star Trek: The Next Generation: In "Future Imperfect", this is how Riker sees through the second fantasy world. In the first, he recognizes his dead "wife" as a fictional character, and the illusion is shattered. But he realizes he's still not in the real world when his cellmate refers to their captor as "Ambassador" Tomalak. Tomalak would be properly addressed as "Commander", and he was only called an ambassador in the previous illusion. Riker never mentioned this, so he deduces that his cellmate is somehow involved in the situation.
- Stitchers features a particular version of this in the episode "Pretty Little Lawyers"; after they accuse the killer of poisoning the victim, he names the exact poison used to kill her before anyone else brought it up.
- In Supernatural episode "The Man Who Would Be King", Bobby admits to Castiel that he had suspected Cas of working with Crowley against The Winchesters. Hardly a breath later, Cas (who has just regained Bobby and Sam's trust) references an earlier conversation... that he heard while he was invisibly spying on the boys. Oops.
- On S.W.A.T. (2017), Hondo and Deacon are investigating attacks by a mountain gang called the Mercs on a team called the Jackals. They head to the mountains to check with Deacon's old partner, Hawkins, who had gone deep undercover with the Mercs. Hawkins talks to them on the Mercs and how they act up, not surprised they'd attack the Jackals. At which point, Hondo snaps that they never said which gang the Mercs were targeting. It turns out Hawkins has gone dirty and taken up leadership of the Mercs for real.
- Used interestingly in an episode of Taggart: A woman gets information about a serial killer from one of his survivors, information that was not mentioned in newspaper coverage. She then uses that information so that her lover can kill her husband and set up the scene to make it look like the serial killer. Unfortunately for them, the husband was the serial killer in the first place.
- Taken: In "Maintenance", Jesse Keys realizes that "Dr. Patterson" is an agent of the UFO project as he is aware that the little men that he sees are grey without being told. He renders the agent unconscious and escapes.
- Subverted in Terra Nova: after a false confession is revealed to be false despite knowing specific details of a crime, Shannon and Washington realize the actual guilty party made sure that the details were spread around to the colonists to cover any potential slip-ups he might make.
- Used on This is Wonderland. A white woman beats up a black man, thinking he was trying to rape her. He takes her to court, and she is so expecting the race card to get played that the following conversation ensues:Crown Prosecutor Kaye: Or was it just because he looked like a rapist?
Defendant: This has nothing to do with him being black!
Crown Prosecutor Kaye: Black? I just said he looked like a rapist. You're the one who attached "black" to "rapist".
- A Touch of Frost: The eponymous Frost pulls off a straight "but I never said it was murder" version. It fails as the suspect calmly points out the police don't send senior officers to inform people that their employee has been in an traffic accident.
- Vera: A slight variation in "Old Wounds", as the police already know the man they are arresting is guilty of murder, but his words reveal other information he should not have known. A man murders the man he believed he murdered his daughter (although he was actually innocent). When Vera arrests, the father says that he had only done to the victim what he had done to his daughter: sneaking up on him and killing him by surprise. Vera notes that the daughter's manner of death had not been made public, meaning that someone with access to the investigation has been leaking information.
- In an episode of Warehouse 13, an agent is discovered murdered under strange circumstances, and the team tracks down his old girlfriend to ask her some questions, during which she asks whether there have been any more electrocutions. Later, they realize nobody ever mentioned he was killed by electrocution. (Turns out she was also a Warehouse agent, who ran off when her boyfriend was killed during an investigation, and knows exactly what did it.)
- Tragically subverted on Westworld. William spends the entire second season thinking the whole "Host Uprising" is all a game being played on him by Ford. When his daughter, Emily, comes to help him, she realizes William thinks she's a host as part of the game. When she brings up the psychological profile card William once had, William shoots her and gloats on how "you got sloppy, you overreached. I never told anyone about my profile. You gave yourself away" He then checks the "robot's" body... and the card falls from Emily's limp hand as she had found it years ago in the music box her mother hid it in. A horrified William realizes he just murdered his own daughter.
- In a second season episode of White Collar, an old friend of Neal's landlady shows up, fresh out of prison, looking for another big score. Neal has to go undercover with the guy to try and take down the murderer running the scam. The old friend almost pooches it by letting slip a bit of info he shouldn't have. Good thing Neal can tap dance on air when things get sticky.
- A suspect in Without a Trace makes a pretty bad one of these. After only hearing a missing man's name and seeing a headshot of him, claims he'd "never hurt a guy in a wheelchair". Whoopsy.
- One of the ways a murderer can give themselves away on Whodunnit? (UK). For example, in "Portrait in Black", the killer knew the subject of the photo the Victim of the Week had been developing in his darkroom when he was murdered, despite the photo being completely overexposed when the body was found.
- The Wire:
- Inverted in the Season 2 episode "Stray Rounds", in which Bodie's Barksdale Organization crew got into a gunfight with another gang over control of a corner, leading to a stray round going through a window of a nearby house and killing a 9-year-old civilian. Stringer ordered Bodie to clean all the guns and drive with Shamrock to the harbor to dispose of them. Bodie doesn't look off the bridge when he tosses the bag with the guns and it falls onto a a passing barge. The cops get hold of the guns, and Bodie is arrested and hauled downtown to the Homicide interrogation room. Detectives Cole and Norris try their hand at Bluffing the Murderer by showing Bodie three of the guns the cops recovered and claim that they found his fingerprints on one of them. Bodie knows that he cleaned all of the guns very thoroughly, so he asks the detectives which one supposedly had his fingerprints on it. Cole points to a gun Bodie never used.Cole: [pointing to gun, smiling] That's you right there.
Bodie: [shaking his head] Lawyer.
- Another example is tragic. During an interrogation, Herc accidentally reveals too much about his informant (Randy), which gets the kid branded as a snitch, his house firebombed, his foster mother killed, and his life generally ruined.
- An example entirely between criminals: Brother Mouzone clues in to the fact that Stringer was responsible for Omar coming after him because Stringer seems to know that there was more than one assailant.
- Inverted in the Season 2 episode "Stray Rounds", in which Bodie's Barksdale Organization crew got into a gunfight with another gang over control of a corner, leading to a stray round going through a window of a nearby house and killing a 9-year-old civilian. Stringer ordered Bodie to clean all the guns and drive with Shamrock to the harbor to dispose of them. Bodie doesn't look off the bridge when he tosses the bag with the guns and it falls onto a a passing barge. The cops get hold of the guns, and Bodie is arrested and hauled downtown to the Homicide interrogation room. Detectives Cole and Norris try their hand at Bluffing the Murderer by showing Bodie three of the guns the cops recovered and claim that they found his fingerprints on one of them. Bodie knows that he cleaned all of the guns very thoroughly, so he asks the detectives which one supposedly had his fingerprints on it. Cole points to a gun Bodie never used.
- The X-Files: In "Small Potatoes", Mulder stops a seemingly innocent man in mid-speech, saying, "Hey wait a minute, wait a minute: how did you know my name was Agent Mulder?" The man runs.