"I think I saw that one."
There's a Serial Killer on the loose! He may or may not be the poetic kind, but there is one thing we know about him: he picks his locations very carefully. So carefully, in fact, that it's almost inevitable that each death connects with each other death to make the shape of... something. Maybe it's a inverted pentagram or just a big arrow.
Alternatively, there's no killer, just a lot of weird stuff happening. To find the Weirdness Magnet, you have to map out where all the weird stuff is and find the exact center.
Related is the String Theory trope, which is more about connecting evidence and people together with string on a cork board, rather than on a large map.
- In Count Cain, the evil organization Delilah were buying up properties which, when plotted on a map, formed a pentagram in order to use the entire city of London in a resurrection spell.
- Detective Conan has a variation with criminal fires to write the kanji for well... "fire".
- Also in the movie Detective Conan Film 13: The Raven Chaser has connected murder cases with Mahjong tiles placed near the victims. It's later found out the crime scenes mapped out a star constellation.
- Dramatically done in the Fullmetal Alchemist manga: it turns out all of the conflicts that had excessive bloodshed involving the government in the history of Amestris could be connected to form a giant human transmutation circle that spans the whole country.
- In the second episode of Re: Cutie Honey, one of the villains goes on a rampage in the city, trashing buildings in a pattern which forms a kanji message insulting the heroine when viewed from above.
- Batman: In Mr. Polka-Dot's first appearance, his crimes mark out a stick figure on the map. Batman deduces that the next crime will be at the point that marks the head.
- In Batman/Spawn: War Devil, the villain plants explosives in the shape of a pentagram.
- Done in one Don Martin Captain Klutz misadventure; the Captain plots Mervin the Mad Bomber's attacks on a map, which form an arrow pointing at the Captain's present location. The pin which marks the tip of the arrow is of course a disguised bomb.
- One theory, which is also presented in the Alan Moore graphic novel From Hell, is that Jack the Ripper's murders were to draw a pentagram on the London map.
- Another theory is that he actually did draw a cross, and was attempting to draw one of those Jesus Fish, as well, in some sort of Satanic Take That! against Christianity. This theory hasn't exactly caught on in most academic circles. To put it mildly.
- Also used in the Indigo Prime story "Killing Time", although with added killer rabbits, multidimensional trains and death-by-harp.
- A Justice Society of America arc had the Rival (an evil speedster and arch-enemy of Jay Garrick) run through the United States, killing people in a certain pattern. It spelled out "Edward Clariss," the Rival's real name...and Jay immediately figured out that the last target was Keystone City and his wife.
- One of the best (though it's not on a map) is in Grant Morrison's Marvel Boy, in which the title character - the hero, mind you - rampages through NYC to spell out a message to humanity. The message? "FUCK YOU."
- In The Simping Detective, Jack does this after his new boss, Sector Chief Daveez tells him to suspend his investigation into a number of deaths around the sector. Jack initially thought the deaths involved were all unrelated, but Daveez's orders make Jack curious. He finds that the deaths all occur within a relatively short radius from a church, which turns out to be a front for the production of Crystal Blue.
- In the Buffy the Vampire Slayer / Law & Order: Special Victims Unit crossover fic "Not All Monsters Are Demons", Buffy Summers, assisting the police in tracking down a serial killer, figures out that the bodies are aligned in such a way as to point to the next body's dumpsite, and that the entire thing makes up a gigantic mystic sigil of some sort... but that the killer is getting the details wrong so the "mystic ritual" the man is trying to put into play just isn't going to work.
- Arachnophobia uses this when Dr. Jennings is figuring out where the spiders' nest is. Naturally, given his crippling fear of spiders, it's his own house.
- In Ghostbusters (2016), the team locates the villain's lair by mapping out recent hauntings.
- Near the beginning of Glass (2019), The Overseer's son Joseph plots out the area where The Horde has been abducting his victims, but there's no pattern to it, and Joseph likens it more toward hunting grounds, with the Horde himself being located elsewhere, with easy accessibility to the abduction area.
- In The January Man, the killer is murdering one woman per month starting in January: when seen on a map, the sites of the eleven murders form the constellation Virgo, and when photographs of the buildings are lined up, the floors on which the murders were committed are the notes on the scale that form the song "Calendar Girl". Yes, really.
- And the dates of the month on which the murders occur are, as the hero realizes when he sees a passing PRIME MEATS truck, prime numbers. As there are 12 that are less than or equal to 31, and 11 of them have been used on the eleven previous months, he's able to tell, which building, which floor, and which day the murder will occur.
- In Night Watch (the film, not the book) mapping the vampire attack incidents gives a pentagram.
- Happens in Sherlock Holmes (2009), due to the villain trying to make it look like he is an Evil Sorcerer and therefore marking out a pentagram, and later a cross, with the murders.
- Silence of the Lambs has a variant - the pattern is random, but "desperately random," as Lecter put it — both the killer and his first victim were from the same area; later victims were abducted from random locations in an attempt to hide that fact.
- In Split Second (1992), the monster kills its victims in specific places in order to draw a dot-to-dot version of an astrological symbol on the city map.
- Film, and thus, Real Life subversion: In Zodiac, despite the best attempts of Paul Avery, David Toschi, Robert Graysmith and everyone else involved, there is never a real perceivable pattern in the Zodiac Killer's killing, and thus, the real killer is never found.
- Agatha Christie liked to play with this trope. Often, the murderer is following a pattern to conceal their real target.
- The ABC Murders: A serial killer is murdering victims in alphabetical order. They killed the first two to cover up their motive for the third.
- After the Funeral: The killer purposefully laid evidence to try and connect an otherwise natural death to the real murder in order to release herself from suspicion.
- A Pocket Full of Rye: The killer is following the nursery rhyme.
- Three Act Tragedy
- Used in Another Note. The Serial Killer sends evidence that the next target lives in a particular condo complex, and has the initials B.B. Two people in the complex match that description, and Naomi and Rue evacuate them to a 5-star hotel. The last victim is actually Rue himself. It turns out he is the Serial Killer Beyond Birthday they've been looking for, and he had this planned all along.
- Averted in Ellery Queen's Cat of Many Tails; while the deaths are plotted on the map, the pattern is irrelevant. (There turns out to be a far more sinister link between the victims.)
- Jorge Luis Borges's short story "Death and the Compass" is an early subversion. The Amateur Sleuth carefully deduces that a series of three murders (that seem kabbalistically-related) committed at regular intervals in the North, East and West areas of the city, imply that a fourth murder will take place in the South, completing a perfect rhombus that symbolizes the four-letter name of God. He goes to the expected place at the expected time hoping to prevent the murder, only to find out that it was all a Batman Gambit by a personal enemy of him to lure him to this deserted spot, and kill him.
- Which ironically winds up playing this straight anyway: the pattern itself holds up and ironically even for the exact same reasons as the Amateur Sleuth thinks they do; it's just that the pattern is not the main motivation for the killer.
- The protagonist even compliments the killer for his clever plan, and suggests a way to put it in action to the same effect in their next lives, with one less murder: make his murders in points A and B, and then wait for him in point C, midway on a straight line from A to B.
- The organizing principle of Reginald Hill's Dialogues of the Dead. There's just one problem: while Dalziel and Pascoe figure out the connections, they never realize that they've mistaken the killer's identity.
- The above quote comes from one of the Genre Savvy characters in A. Lee Martinez's Gil's All Fright Diner. He does exactly that and finds that the diner itself is the Weirdness Magnet.
- The "weirdness magnet" version shows up in Good Omens, where Anathema Device is charting ley lines and discovers said lines are forming a spiral converging on the town of Lower Tadfield.
- In The Haunting of Alaizabel Cray, the location of a series of murders forms the shape of the Chackh'morg — basically an Eldritch Abomination.
- Judge Dee is unsurprised to discover that two or more of his murder cases are actually linked to the same criminal plot - even when the victims involved seem to have no connection at all.
- In the second Mercy Thompson, book the Big Bad is demon-possessed and causes violence by just being nearby. The good guys try to locate him by tracking the outbreaks of violence but no pattern is visible at first. The pattern shows up when they look at day-time incidents only - being a vampire, the villain can't move around to cover his tracks in daylight.
- A Night in the Lonesome October uses the weirdness magnet version. A contest between magic-users is fated to take place at a Place of Power which none of the contestants knows the location of at first; they have to map out certain significant events to figure out where it is. It takes them most of the story to find the place because one of the events they're all including in their calculations is actually just a coincidental piece of unrelated weirdness. The narrator recalls that one year's iteration of the contest had to be called off entirely because none of the contestants could figure out the location for the showdown.
- Michael Slade's Ripper, serial killings in Vancouver are arranged to trace a pattern of triangles derived from a Tarot card.
- Tortall Universe: In Terrier, Beka maps out the Shadow Snake kidnappings, since she knew her lord did something similar with his big cases, looking for patterns.
- Done in the Angel episode "Apocalypse, Nowish" using a map of recent mystical disturbances to find out where the Beast was heading.
- In the Criminal Minds episode "Masterpiece", Reid connects the sites of a series of murders to a Fibonacci spiral, with an incrementing number of deaths at each location, all centered around what he concludes must be the murderer's house.
- Another killer made a heart with his victims (well, with a little imagination it's a heart) to show his love for another serial killer's widow.
- Averted on CSI, when confession-notes left on bathroom stall doors provided a clue to track a truck-driving serial killer. Although the graphic showing how all the restrooms' locations lined up resembled a Connect-The-Deaths diagram, the killer's girlfriend/accomplice is the one who left the clues, and the line merely plotted out the trucker's delivery route rather than a symbol.
- CSI: NY:
- Inverted when a killer is identified because he'd turned on the lights in his downtown office suite, breaking the pattern of lights in which the victim had spelled out "Marry Me," as a grand romantic gesture.
- Played straight in another episode when Mac plots the three locations where a victim's body parts have been found, but whose head is still missing, and discovers that the sites are corners of the neighborhood formerly known as Hell's Kitchen. When they search the fourth corner, they find the missing head.
- In a double episode of Diagnosis: Murder, a serial bomber wrote the name of her dead father on the city map. The absurdity of this is Lampshaded by Detective Steve Sloan, who draws a pig in the same pattern, though of course, Dr. Sloan is right.
- Doctor Who: In "Arachnids in the UK", Jade has a map showing all of the strange spider activity occurring in Sheffield. The Doctor starts drawing lines connecting them and, when she's finished, she has what looks like a spiderweb with Robertson's hotel at the center.
- The 'weirdness magnet' version was often used on Eureka by Carter and the scientists to track down the cause/source/solution to the mad science problem of the week. Good example: in "The Ex Files", using rocks and other items to stand in for locations allows Carter and hallucinatory Stark to realize the resonance-frequency oscillations which are shaking things apart are moving toward G.D. not away—and thus the device at G.D. they thought was the cause was actually the target.
- Fringe actually did this with the mysterious Pattern in the first series finale. Each of the Pattern incidents were located near existing weak spots in the fabric of reality, and the Weirdo of the Week was attempting to open a doorway to another universe at these weak points.
- On Get Smart, the Chief is showing Max a map of North America with pins representing identified KAOS agents. Max asks about the one "agent" with no obvious explanation, way up in Manitoba. He pulls out the pin and the entire map falls to the floors knocking out the other pins.
The Chief: He was holding the map up!
- Grimm season 5 episode "Star-Crossed" features a Wesen serial killer who ritualistically crucifies his muggle victims- mapped out, the kills follow the shape of the big dipper.
- Subverted/criticized in Jonathan Creek, where a TV crime show decides that a serial killer is killing women if their names are the names of flowers, dubbing them the Daisy Chain Killer, purely because it makes a good story. In the end, it turns out the killer was just generally disturbed and killing randomly, and only one of their victims had a flower name — the second victim that supposedly started the pattern was killed by someone else for unrelated reasons, using the serial killer as cover.
- Kamen Rider Decade used this in the Kuuga story arc. The Grongi are killing policewomen as part of their Gegeru ("game"); Tsukasa/Decade, posing as a policeman, suggests that the victims' birthdays spell out "Kill everyone" in goroawase, letting them know who the fifth victim will be. Later he meets with a female detective and reveals that he lied about his first theory to cover up the truth, that the murders are based on proximity to the Grongi's sealed leader - which is precisely where they are. Then he spoils the Gegeru by punching the detective in the face, since an additional rule was to avoid bloodshed.
- In an episode of the Austrian series Inspector Rex, the main characters face off against a satanic cult that murders women and leaves their bodies so that they form a giant pentagram.
- Law & Order: Criminal Intent once featured a murderer who tried to randomize his crimes, but plotting them on a map showed repetition of a certain irregular shape. He was found out because he had autistic tendencies, and constantly arranged things into that shape without realizing it. The cops spotted him because they noticed things all over his house placed in the same pattern— right down to the pushpins on his bulletin board.
- One Law & Order: Special Victims Unit episode had a killer lining up the arms on his victims to resemble a line of paper dolls when the crime scene photos were placed side by side.
- Parodied brilliantly in obscure BBC buddy cop show spoof Lazarus And Dingwall; What appears to be a serial killer with strange variations in his MO turns out to be two serial killers, using corpses whose names end with 'o' or 'x' to play a giant game of Noughts and Crosses on the map. To prevent the next murder, they must find the correct person with a name ending in 'o'... In the middle of the city's Italian district.
- Life: The Serial Killer from the "Find Your Happy Place" episode killed his victims by leaving them to suffocate in steamer trunks. When plotted out on a map, the trunk locations make a smiley face.
- Averted/Played With in an episode of NCIS: Los Angeles, when crossover guest Abby was the only person to discern that a serial killer's victims were unusually random mixes of ages, races, and sexes (and possibly killing techniques). When he captures her, he notes that he'll be able to cross "Caucasian Female" off his list.
- Practically every episode of NUMB3RS, but in one of the early episodes, the main character develops an algorithm which, based on the inherent human inability to produce random numbers/circumstances, uses a map with pushpins to find where the next murder will/would have occurred.
- Parodied in People Like Us, when Roy follows around a police officer. One of the senior officers explains that a map of the borough covered with pins represents a string of recent thefts, and they're looking for a pattern. When Roy asks if they've found one, the officer replies. "Yeah - it looks like a rabbit." It does, in fact, look exactly like a rabbit.
- In the teen newspaper drama Press Gang, Linda was locked in an airtight vault with a half-broken phone. When she didn't turn up at work and four co-workers all reported the same weird phone calls in the middle of the night, they drew a cross to find that X marked the spot.
- An episode of RoboCop: The Series had a mad bomber, The Spider. When they plotted out his bomb sites, they turned up a picture of a particular type of spider web.
- In Sue Thomas: F.B.Eye, Sue realizes that the sites of a serial killer's murders form a constellation. One point doesn't fit the pattern, which leads them to a copycat killer.
- An episode of The X-Files had a killer whose pattern formed an upside-down number nine (which was to be the intended number of victims). He was apparently unconsciously acting according to some numerological idea rather than doing it deliberately.
- In Young Blades, Siroc connects several kidnapping sites on a map and adds another point to form an obelisk, predicting that this point is the site where the victims are being held.
- In Batman: Arkham City, Azrael is the Weirdness Magnet, drawing random-looking patterns in the ground wherever Batman encounters him until they all line up and make a map to where you can find him.
- Strange example: The cover for the US manual of Heavy Rain has the deaths forming the shape of one of the origami figures. This...has absolutely nothing to do with the case at all in-game.
- Police Quest III goes for the old standard pentagram killings. In defiance of the top quote, the player doesn't figure it out until after his wife stabbed into a coma.
- In World of Warcraft, this can be done by players. Unlike most other things in the game, player corpses do not despawn; they sit there on the ground for up to a week until reclaimed by their owners. This has, naturally, been abused for everything from rude jokes to gold advertising, by leaving elaborate patterns of corpses lying around a major city.
- In 8-Bit Theater, Thief and Black Mage attack a series of towns so that their rampage will spell out "You are next" on a map of the Dwarven Kingdom (when we're shown the map, the t is still missing). In cursive. Naturally, the Dwarves can't figure it out.
- In The Order of the Stick, Nale arranges a series of murders so that a map of their locations points to the city park, where he's setting a trap for Elan.
- Parodied in this Sluggy Freelance strip, where Torg puts together a map with push pins during his search for Oasis, but the pins don't actually represent anything.
Torg: "It's just a collage I threw together, but it sure makes me feel on top of things!"
- In the Alice Isn't Dead episode "Alice," the Narrator Implies that she collated, then eventually began to map out sightings of her missing and presumed dead wife Alice in the background of news reports on various deaths and disasters, leading her to become entangled in The Conspiracy Alice had been investigating prior to her sudden disappearance.
Narrator: I made a list of every place I saw you on the news, and that list became a map of America.
- Referenced in Archer episode Lo Scandalo when Krieger gives the entire ISIS staff each a package containing part of a murder victim. He tells them specific dumpsters, to form a smiley face. Averted, however, as they just dump it wherever they feel like.
- In Central Park, Season 1 "Dog Spray Afternoon", A non-murder example. Owen, the park staff, and Molly sings "Method to This Madness", where they sing about finding a pattern on the Central Park map to predict where the "Shart" tagger will tag his next location. Molly is able to figure out the pattern when she connects to dots on the map of the tagger's tag and sees that he's trying to spell a giant "SHART" on the park.
- In one episode of Inspector Gadget, a series of very minor crimes committed by MAD agents, when plotted out on a map of Metro city, spell out MAD. The intent of this plan was for Gadget to figure this out and be waiting for them at the final crime scene, where they had laid a trap for him.
- The Magician: one villain sets fires in the city, Ace goes to the police station and shows that the locations form the letter M - as in Multifire (the name of the villain in question), then the officer arrests Ace, for being "the Magician" (his sign was also an M).
- Parodied (what else) in The Simpsons episode "Homer The Vigilante": the police are investigating a series of robberies (not murders) using the map technique. After the titular family reports theirs and the police add it to the map...
Chief Wiggum: Well...there doesn't seem to be any pattern yet... But I take this one and move it here...[moves a pin]...and I move these over here...[moves more pins] Hello! It almost looks like an arrow!
Lou: Hey, look, Chief! It's pointing right at this police station!
Chief Wiggum: Let's get out of here!
[All the cops flee in terror]