Serial Killings, Specific Target

"When do you notice a pin least? When it is in a pincushion! When do you notice an individual murder least? When it is one of a series of related murders."

—Hercule Poirot, The ABC Murders by Agatha Christie

A killer has a particular target in mind. However, if that victim just turned up dead then the killer would be an obvious suspect. So the killer decides to kill a bunch of other people who share characteristics with the intended target to make the murders look like the work of a serial killer.

BE WARNED: Spoilers abound on this page.

Examples of Serial Killings, Specific Target include:

Anime and Manga

Case Closed: A serial arsonist turns out to be doing this, inspired directly by The ABC Murders.
Subverted in The Kindaichi Case Files: supposedly a serial killer has gotten loose and is killing everyone trapped in the Closed Circle, but Kindaichi figures out that they're all connected. While the murderer is looking for one specific person, he doesn't care that he's killing innocents in the process.

Comic Books

The serial killer targeting elderly couples in the "Blades" story arc from Batman: Legends of the Dark Knight #32-34. The killer is the heir of one particular couple.
In The Maze Agency story "The Return of Jack the Ripper?", an unrelated attack on one member of the Ripperologists gives a member the inspiration to kill their intended victim then try to kill the other members of the club to make it look like a an organised series of attacks (including the first, unrelated attack).

Film

A variant is done in the 1944 Sherlock Holmes film The Pearl of Death: bad guys are looking for a pearl which was hidden in one of six china busts of Napoleon. They track down the owners of the busts and hire the Creeper to kill them, and then break open the bust to see if it's the right one. To cover their tracks, the Creeper breaks all of the victim's china, to disguise the fact that they're only really interested in the Napoleon busts.
Seems to be the case The Nail Gun Massacre. The rapist construction workers that are the actual targets are being killed along with tons of other completely random people.
This is revealed to be the case in Satan Claus. Sharon discovered her boyfriend was cheating on her with the police captain's wife, so she killed her, then used voodoo to take control of the captain and make him kill her boyfriend. The Santa motif and the rest of the murders were just done to throw the authorities off, making them think there was just some psycho going on a random killing spree.
In The Sleeping Car Murders a woman is strangled in her sleep before the train reaches Paris. However the woman was chosen at random to hide the later murder of another passenger. One of the murderers is a police detective and knows that the police will concentrate on those with a motive to kill the first victim and consider the other murders of all the people in that compartment as getting rid of witnesses.

Literature

The ABC Murders by Agatha Christie. The killer sets up an alphabetical motif: someone whose name begins with A is killed in a city that begins with A, and so forth. The "C" murder is the significant one; the victim is a wealthy man, killed by his brother in order to inherit his vast estate.
- Another Christie example is Three Act Tragedy. Three people are killed by poisoned drinks at three separate dinner parties. The second murder is the significant one, while the third served to cover it up. The first murder turns out to have been merely a dress rehearsal for the second, with the victim chosen at random.
In the 87th Precinct novel Long Time, No See by Ed McBain, a murderer wants a particular blind person dead, so he kills a number of other blind people to make it look like the work of a serial killer.
- This happens enough in the series for the detectives to have a shorthand term for it, "classic smokescreen."
In the Simon Ark story "The Avenger from Outer Space" by Edward D. Hoch, a killer makes a carefully planned series of murders look like the work of a local lunatic.
The Elizabeth Peters novel The Murders of Richard III has a variation of this: rather than murders, there are a series of embarrassing but non-lethal pranks designed to mimic the murders attributed to Richard III in Shakespeare's play. The prankster/murder's intention is that the last prank will "go wrong" and end up killing the target.
The David Eddings novel Regina's Song has the killer butchering about two dozen sexual predators in the Seattle area. Although in this case the reason for killing so many of them wasn't to cover up the specific target, it was because Renata didn't know where to find the specific sexual predator who raped and murdered her twin sister, and so just went trolling for rapists until she found the one she was looking for. It is implied that she would have stopped killing after that point even if she hadn't been caught afterwords.
Burke mentions this was a favorite tactic of Career Killer Wesley. He would kill one man, then burn down the building so the police would have a bunch of other possible victims/motives to investigate.
In The List Of Adrian Messenger a killer destroys a train and a plane just to get one person in each as part of a long range plan.

Live Action TV

Monk: Episode "Mr. Monk and the Really, Really Dead Guy": A doctor kills his date, but realizes that the cake in her stomach has gold leaf, which would show up in an autopsy and lead police to the one restaurant that does this and he'd get caught. So he kills one street performer in a ritualistic manner similar to a serial killer and sent messages to the police proclaiming himself as one to distract detectives until the stomach content decomposes.
- Monk also did it in another episode where a guy tried to get away with poisoning a chocolate bar that his wife liked by poisoning many other bars of the same brand and leaving them in amongst non-poisoned ones in the store. Her death would then look like one of the random victims of an anonymous serial killer. I think it also explains one possible theory behind the real-life Tylenol poisonings in Chicago.
  - And inverted in yet another one, "Mr. Monk and the Voodoo Curse," where a paramedic leaves Voodoo Dolls in delivery packages at the homes of dead or dying patients she shows up to save, giving the impression the dolls were already there when the person died and that it is either the work of a very crafty serial killer, or even that some kind of magic was involved. She finally sends one to her still living elderly uncle, who she then poisons with an untraceable drug for the inheritance, but he is the only one she actually to be murdered as the others died in freak accidents (hit by a baseball or struck by lightning).
  - The episode "Mr. Monk's 100th Case" takes a twist on this type of spree. In this one, a serial killer is strangling young women and stealing their lipstick (a calling card). However, it turns out that the supposed fourth and final victim of this killer is in fact the work of a copycat trying to frame the original killer.
In the pilot of Castle, the killer murders his sister for her money, then stages the murder to look like something out of one of Castle's books and commits two similar murders so it'll look like one of her clients—who's obsessed with the books—did it. Castle sums up the trope beautifully:

Alexis: How do you get away with one murder by committing two more?
Castle: At one death you look for motive, at two you look for connection...at three you look for someone like Kyle [the above mentioned obsessive fan]; at three you don't need motive because mentally unstable serial killers don't usually have one.

In an episode of CSI a comedian dies from drinking a poisoned bottle of water. The a kid dies from drinking the same brand. The first victim was the target, the killer (a rival comedian who hated his style) says he blames the CSIs for not finding the poisoned bottle in time as he's arrested after confessing out of remorse.
Done accidentally in an episode of The Seventies TV series Ellery Queen. A movie is being filmed based on Ellery and the man playing Ellery is killed by a gun that was supposed to be filled with blanks. Then a little while later - after recasting Ellery - the stunt double is killed in a stunt gone wrong. Is the production cursed? Is someone out to shut it down? It turns out that the stuntman was the target in the first place; he was originally supposed to do the getting shot stunt, but the scene was changed at the last minute, and the killer couldn't switch the guns back before it happened.
In The Red features a serial killer targeting bank managers who turns out to be this trope.
CSI New York: In "Page Turner", the killer poisons his wife with thalium and then coats a book in the library where she works, knowing that others will be exposed to it. After another two people die, he launches a law suit against the city and the library.
Rizzoli and Isles: In "Rebel Without a Pause", a sniper misses their shot at their target on their first attempt and kills someone else. They do another random shooting to make the police think this a series of random attacks before making another attempt on their original target.

Real Life

It has been theorized that John Muhammad, the DC Beltway Sniper who randomly shot and killed 11 people and wounded six more, was eventually going to kill his ex-wife, knowing that the police would not automatically look at an ex-husband as a suspect if they thought she was just a random victim.
Ronald Clark O'Bryan (nicknamed The Candyman) (October 19, 1944 – March 31, 1984) was a murderer from Deer Park, Texas (near Houston), who was convicted of killing his eight-year-old son Timothy on Halloween, 1974 with cyanide-laced Giant Pixy Stix candy in order to claim life insurance money. It's alleged he tried to cover his tracks by giving poisoned candy to other children in an attempt invoke the Razor Apples Urban Legend. However, Elizabeth, his daughter, and none of the other children ate any of the poisoned candy.