The first team is investigating a man found shot dead downtown. In the B-plot, the second team is examining a woman found strangled dead in her bathroom. Turns out they both had the same hairdresser. Could it be that both teams are WorkingTheSameCase?

This is a useful technique to add a minor twist to help shows with [[TwoLinesNoWaiting two concurrent cases]] feel a little less formulaic. Used at least once a season in ''Series/{{CSI}}''.

A variant is for the senior officer, fed up of the CowboyCop's attitude, to tell him he won't be involved in the big murder case, and will be investigating a break-in at a laundromat the night before. The Cowboy Cop will soon realise, possibly in a EurekaMoment, that it's the same case. He will be careful not to let anyone else in on this, assuring his superiors (truthfully) that he's still following up that laundromat robbery.

See also StrangersOnATrainPlotMurder, MinorCrimeRevealsMajorPlot.

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!!Examples:

[[foldercontrol]]

[[folder:Comic Books]]
* In ''Comicbook/TheSimpingDetective'', Jack discovers that he and Galen Demarco are working the same case. Jack is investigating the deaths of several mob underbosses, while Galen is looking into the disappearances of alien prostitutes. Galen wants Jack to back off, until [[ComicBook/JudgeDredd Dredd]] suggests they work together. [[spoiler: Turns out, Bob, the bartender at [[BadGuyBar The High Dive]], is drugging the girls with a chemical which [[DeathBySex reacts violently with semen]], causing [[StuffBlowingUp massive explosions]].]]
** The whole point of the "Trifecta" crossover is that halfway through it turns out that Jack, [[ComicBook/LowLife Dirty Frank]] and [[Comicbook/JudgeDredd Dredd]] are ''all'' working the same case.
* Said word for word by Comicbook/BlackWidow in the "Death of the Dream" storyline in ''CaptainAmerica''. She, TheFalcon and {{Agent 13}} are all looking for [[BuckyBarnes Winter Soldier]], but for vastly different reasons.
[[/folder]]

[[folder:Film]]
* In ''Film/LAConfidential'' it turns out that ''all three'' of the good cops (or anyway, the not so bad cops) are working different angles of the same case.
* ''Film/DieAnotherDay'': After being rescued by Bond, the mysterious Jinx reveals that she's an NSA agent--in a slight subversion, Bond has already realized that she's one of the good guys--and that they're both pursuing the same villain.
** In ''Film/CasinoRoyale'', Felix Leiter introduces himself to Bond this way during the poker game. After Bond loses his money, Leiter agrees to stake Bond back into the game under the condition that the CIA be the ones to take Le Chiffre into custody.
* Happens in ''Film/KissKissBangBang'', in that Harmony's sister hired Perry to investigate what ended up being a murder. [[spoiler: Subverted in that Harmony [[NeverSuicide actually committed suicide]]]]
** Harry Lockhart realises that Perry's surveillance job (and the murder that occurred during it) and the disappearance of his friend's sister are connected because the same plot device was regularly used in a pulp fiction series that is significant to several of the characters involved.
[[/folder]]

[[folder:Literature]]
* OlderThanTelevision: This trope has been around a while. In almost every ''HardyBoys'' book, the boys and their Police Chief father were WorkingTheSameCase.
** Not just with their father. During the 80's and the Present, Frank and Joe have been frequently crossing over with NancyDrew in two different series both titled ''The Nancy Drew/Hardy Boys Supermysteries.'' While a certain number of the cases had them know they were working together outright, more than a few involved them arriving at the same location for different cases, finding out the other is there, meeting up to pick each other's brains, and revealing their cases are somehow threaded together.
** In at least one of the crossover books, they're working the same case, but from opposing sides--Nancy is trying to prove a man's innocence, while the guys are trying to prove his guilt, and every bit of information or evidence found is interpreted respectively by each person.
** This is actually averted in the very first book, when the boys think that Nancy's bad guy might be theirs as well, but he isn't.
* Harry Dresden in ''Literature/TheDresdenFiles'' will often end up working separate cases that turn out to be related, though in later books his problems are just as often unrelated.
* In the Robin Cook novel ''Blindsight'' (not to be confused with the Peter Watts novel of the same name), Laurie gets into repeated arguments with her police friend about which is more important: a string of cocaine overdoses among previously upstanding rich kids, and a series of gangland murders. [[spoiler: It turns out that a recently blinded mob boss is a bit impatient for his cornea transplant and is working on both ends of the problem. In order to make sure that the organ donors were in an acceptable condition, he had them die of a forcible cocaine overdose, followed by being stuffed in the refrigerator until the police arrived. As for the waiting line of patients, it didn't particularly matter how they died.]]
* ''Discworld/{{Thud}}'' - whilst most of the Watch are trying to find out who killed a dwarf rabble-rouser, [[ThoseTwoGuys Fred and Nobby]] decide to investigate an art theft, with the specific intent of staying very far away from rioting dwarfs. It doesn't work out that way.
* Happens occasionally to StephaniePlum and Joe Morelli. Tends to lead to her winding up in dangerous situations and/or blowing his case because he never tells her things she needs to know.
* A common occurrence in the RetrievalArtist series, when Miles Flint, the retrieval artist working outside the law, is investigating the same affair that the Armstrong lunar police force has been tasked with, for his own purposes.
* Shows up in Elizabeth Honey's ''Literature/RemoteMan''. Kate is outraged by the disappearance of a rare native python and begins investigating the man she believes responsible, an American tourist nicknamed the Cowboy. She attempts to get her cousin Ned, currently staying in Massachusetts, but he and his friend are sidetracked when the bear they had been searching for in the forest is killed and her cubs are stolen. About halfway through the book, we learn that the Cowboy is responsible for the bears and several other poaching jobs worldwide.
* AnitaBlake: Back when the books still had plots, whoever tried to hire Anita to raise a zombie in the first chapter would somehow be involved in the main mystery of the book.
[[/folder]]

[[folder:Live-Action TV]]
* This happens a lot of times in ''Monk'', both the episodes and the books.
** The {{pilot}} for ''Series/{{Monk}}'' included Monk being called in on two unrelated cases, in fact by two different police divisions, only to later discover that the same man committed both murders.
** In "Mr. Monk and the 12th Man," where Monk is called in to a homicide at a toll plaza. Later, to a strangling at a movie theater. The connection: sequential $10 bills at the crime scenes.
** In "Mr. Monk and the Buried Treasure," this is the case, with Monk and Natalie accompanying Dr. Kroger's son and his pals into the hills following a supposed treasure map, which is actually tied to a bank robbery that Stottlemeyer and Disher are investigating. The TwoLinesNoWaiting trope is clearly present, since in the first half, Stottlemeyer's and Monk's investigations are intercut.
** In "Mr. Monk Gets Fired," the police commissioner is furious that Stottlemeyer and Disher are focused on solving an arson-murder at a wig shop instead of a headline-grabbing dismemberment case. Sure enough, the same killer did both.
** In "Mr. Monk Stays in Bed," Natalie feels [[ItsPersonal personally invested]] in solving the murder of a pizza boy who died en route to her house, but the police are too busy looking for a judge's killer. Of course, the judge's killer also killed the pizza boy.
** In "Mr. Monk in Outer Space", Monk is brought in to investigate the death of Burgerville CEO Brandon Lorber, whose shooting death he quickly realizes was actually a heart attack - and the shooter passed off the death as a murder. The next day, he is brought in to consult on an apparently unrelated incident, the shooting of ''Beyond Earth'' creator Conrad Stipe at a convention. The day after that, a cab driver named Phil Bisson is shot and killed in what Monk deduces as being a staged robbery. It is this third murder that causes Monk to deduce that Lorber and Stipe were shot by the same person - he finds a piece of chewing gum that is the same brand as a piece that Stipe was chewing before he was killed, and a wrapper from a coffee candy in Lorber's office. [[spoiler:The shooter was a hired hit man. Bisson was the cab driver who drove the hit man away after he shot Lorber's body. During the ride to the airport, the hit man lost his Blackberry, which had incriminating messages between him and his employer and information on Lorber. Stipe answered it when the hit man called it from an airport payphone. The hit man killed Stipe and the cabby as he couldn't risk that either of them had browsed his messages.]]
** In "Mr. Monk and the Dirty Cop", the murders of two men, Paul Braddock and Bill Peschel are being investigated by different parties: Lt. Disher to Braddock's death, and Monk and Natalie to Peschel's death. Monk eventually finds evidence that both were killed by the same person.
** In "Mr. Monk Goes to the Firehouse", Monk and Natalie stop by a North Beach firehouse to investigate the death of [[spoiler:Sparky]], a beloved firehouse dalmation bludgeoned with a pickaxe during an apparent break-in. They also stop by a nearby house fire in which a 64 year old woman, [[spoiler:Esther Stoval]], was killed. Monk deduces that Esther's death was actually a FieryCoverup. Her house, we learn, was one of several scheduled for demolition for a new condo complex. When Monk, Natalie and Stottlemeyer question [[spoiler:Lucas Breen, the developer]], Monk immediately pegs him as Esther's killer. After Monk and Natalie requestion a dog-loving witness who saw a man dressed as a firefighter leaving the firehouse after Sparky was killed, Monk deduces that [[spoiler:Breen]] also killed Sparky. [[spoiler:Breen left his overcoat at Esther's house. He went to the firehouse to get a coat and helmet so he could sneak into the fire and recover it without emergency crews noticing him. He didn't expect Sparky the dog, and had to take him out in self-defense.]]
** In "Mr. Monk and the Two Assistants", Monk, Natalie and Sharona look into a beating death that Sharona's husband has been framed for. When Monk and Natalie go back to San Francisco, they find themselves investigating a staged alligator attack. Monk finds evidence that ties both deaths together.
** Averted and subverted in "Mr. Monk on the Couch": Natalie helps Monk investigate a number of knifings happening in her own neighborhood. However, her own case involving a man who died of natural causes with a fake identity, is not connected to it.
** Subverted. When a BART engineer named Stuart Hewson is shot and killed in his house, Monk deduces that it is tied to three knifings committed by an ex-con because Hewson's house had a view into the bedroom of the ex-con's second victim, Mark Costa. However, Monk also concludes that Hewson's killers are some crime scene cleaners who he has been around the past week. [[spoiler:Hewson had spotted the crime scene cleaners discovering the ex-con's fortune of diamonds in Costa's house. They killed him because he was trying to blackmail them.]]
* ''Series/VeronicaMars'' has a habit of cleverly combining Veronica and her dad's cases, sometimes pulling dismissed plot threads into one cohesive reveal of the season's Big Mystery.
* ''Series/LawAndOrderCriminalIntent'':
** In the two-parter ''In the Wee Small Hours'', both teams were involved. And a fake Nancy Grace. Heavenly.
** In the L&O:CI episode "Purgatory", Eames gets a temporary partner to investigate the shooting of a dealer and two tourists. Meanwhile, a suspended Goren is working undercover as an enforcer for the big dealer suspected of ordering the hit.
* ''Series/{{CSI}}'' had an interesting subversion in that two twins who were SeparatedAtBirth were killed within an hour of each other. The causes of their death have nothing to do with one another and in fact, it seems that there are two separate murder victims, both of whom are the result of very separate lifestyles. [[spoiler: Then its revealed that the twins both used the same dry cleaner. Turns out that the one murder suspect was found out by one of the twins to be photoshopping war photos and he decided to meet her when she picked up the dry cleaning, killing the first twin (the one who wasn't his target). He then went to the real targets house to eliminate the proof of his forgery only to be walked in on the second twin (the intended target). In his justified panic, he kills her as well. Gil calls it as both, seeing as how one case was with a motive and the other was a case of wrong time wrong place, but they were both killed by one man.]]
* Despite having two detective teams, ''Series/LawAndOrderSpecialVictimsUnit'' avoids this, as generally one team works with the direct suspects and the other handles either the evidence or tries to get info from more obscure places.
* In the ''Series/{{Castle}}'' episode "Double Down", Castle and Beckett have a bet with ThoseTwoGuys about who can solve their murder first. Each team finds a suspect, but they both have alibis for their respective murder. The teams call off the bet and join forces when forensic evidence is found linking the victims. Ultimately it turns out [[spoiler:to be a StrangersOnATrainPlotMurder]].
* Easily half the episodes of ''Series/TheGoodGuys'' aired to date rely heavily on this trope. Dan and Jack are intentionally sequestered in the career dead-end of small property crimes, yet as Jack attempts to do his job properly and Dan whines that they ought to be "out there bustin' punks," they inevitably stumble across a much bigger crime in progress, often the ongoing major case their lieutenant specifically barred them from pursuing.
** When [[spoiler:Dan]] is framed for a kidnapping, Jack ignores the theft case he is assigned to and instead pursues the kidnapping case against orders. In the end it is discovered that the kidnappers committed the theft as well so Jack is in the clear.
* ''Series/PersonOfInterest:'' Fusco and Carter spend much of the first season working with Finch and Reese without either of them realizing the other is also part of "Team Machine." They finally figure it out in the season finale, "Firewall," to Finch's obvious amusement.
** In the third-season episode "Last Call", Fusco helps a rookie cop with a murder investigation while Finch and Reese are busy trying to solve a kidnapping. It turns out that the kidnapping was committed in order to coerce someone into helping cover up the murder.
* In the ''Series/MurdochMysteries'' episode "Murdoch on the Corner", Inspector Brackenreid is investigating the death of a pastor who was beaten to death with a blunt instrument, while Murdoch is trying to find a "[[SerialKiller sequential killer]]" who dispatches their victims with a single gunshot. It eventually becomes clear the same killer is responsible, and the deviation from the pattern in the pastor's case is a clue as to the motive.
* ''Series/MurdochMysteries'' does this again in a 2013 episode that has Brackenreid investigating the death of a prisoner who apparently hung himself in his cell, while Murdoch and Constable Crabtree are investigating a brutal robbery in which a shop owner was murdered. They eventually realize that both cases are related.
* The ''Series/{{Elementary}}'' episode "Deja Vu All Over Again" has Watson investigating a woman's disappearance and Holmes investigating the death of another woman who was pushed in front of a subway train. Turns out, [[spoiler: the first woman's husband killed the second woman as part of a complicated scheme to cover up his wife's murder]].
[[/folder]]

[[folder:Visual Novels]]
* ''VisualNovel/JakeHunter Detective Story: Memories of the Past'' has the case "As Time Goes By", where Jake begins the case accepting an offer to investigate the theft of a painting from a family nearby. His assistant Yulia, meanwhile, encounters a lost little boy outside of the office and agrees to help him find his mother, who went missing recently. They both find out the cases are related after encountering one another at an antique shop.
[[/folder]]

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