Detective Patsy

The perp hires a detective to solve the crime, in order to throw suspicion off himself. Typically, the detective in question is a Defective Detective, to minimize the odds of him actually working it out.

Invariably, the detective turns out to be not quite so defective as the perp thought, and figures it all out.

This often leads to monologuing (both from the Detective and the Perp) and the inevitable "The only thing I couldn't figure out was..." statement during the Final Confrontation.

This is an archetypal trope, as even Sherlock Holmes was abused like this.

This trope is often used as a reveal or twist, expect spoilers below.

Comic Books

 * Randall Banticoff does this to Luke Cage in Luke Cage Noir, hiring Cage to investigate his wife's murder while arranging for him to take the rap for the crime - and die before a trial could potentially expose it as a frame job.
 * Taken to the extreme in Sin City where Eva Lord hires private eye Dwight McCarthy to get evidence on her supposedly abusive husband who may be plotting to kill her.

Literature
""You certainly seem to have met every difficulty," said the inspector. "Of course, he was bound to call us in, but why he should have gone to you I can't understand."
 * Nero Wolfe once required a client to sign a statement promising to pay in full, even if he turned out to be the guilty one. It turned out to be a good precaution.
 * Writer Ross Macdonald's characters, particularly Lew Archer, were picked so often for plots like this, it's hardly any wonder that they always demanded payment in advance.
 * Ur Example is probably the Sherlock Holmes story The Adventure of the Retired Colourman. A quote from the end of the story:

"Pure swank!" Holmes answered. "He felt so clever and so sure of himself that he imagined no one could touch him. He could say to any suspicious neighbour, 'Look at the steps I have taken. I have consulted not only the police but even Sherlock Holmes.'""


 * The novel Who Censored Roger Rabbit had Roger hire Eddie Valiant to investigate his boss - so that Roger would have someone to frame when he killed his boss. In the final chapter Eddie admits that the plan would have worked were it not for two complications that Roger had no way of seeing coming.

Live Action TV
"Detective: It was done in Jagged Edge!
 * The Rockford Files seemed to do this a lot, but all shows about private detectives will do one eventually.
 * Usually not applicable to police, but Columbo caught one once, when the murderer was the commissioner. He specifically requested Columbo for the case, having somehow failed to notice that the bumbling detective had only failed to close one case in his entire career.
 * Another police example is the CSI fourth season episode Suckers where a casino owner attempts to fake a huge robbery for the insurance money.
 * In an episode of Poirot, a shifty old lady tried to abuse Capt. Hastings in this way; she had the sense not to go to Poirot directly. In the books, however, Poirot frequently finds himself working for clients with something to hide - though not necessarily murder.
 * Monk had this once:
 * Happens so frequently in Jonathan Creek that merely soliciting his services should be ample proof of guilt.
 * Lampshaded in Dark Justice: a not-so-bright gigolo and his girlfriend hire a female detective to solve the murder of the rich woman he was living off. The detective easily proves it was these two who did the deed, and asks why she was hired. The gigolo says he thought no-one would suspect him if he did.

Girlfriend (to gigolo boyfriend): I wanted to see that movie, but you said no!"


 * A weird one in Murder She Wrote: The murderer is a DA, who killed one of the defendants in a major fraud case. Earlier, he tried to phone her and accidentally called Jessica's number. To cover this up, the DA subpeonas Jessica and refuses to believe she has no idea what it's about. So Jessica has to solve the murder to avoid being found in contempt of court.
 * In Sledge Hammer: the episode "Play It Again, Sledge" has a women hire Sledge as private investigator, to make him an eyewitness of her "selfe-defence" murder.

Film

 * Happens to Jake Gittes at the start of Chinatown.
 * In the movie Ace Ventura: When Nature Calls, Ace is hired by an Englishman trying to harvest bat guano for fertilizer, who has to start a genocidal war between local African tribes to get it. Ace was hired as a means of establishing for the public that he had done everything he could to prevent the war. When Ace unexpectedly figures out who is behind the scheme to wipe out the innocent tribe, the Englishman decides to change his plans and set Ace up as a patsy for the whole thing.
 * Film example:
 * Another classic:
 * The 1987 thriller No Way Out subverts this: Commander Tom Farrell, the man that Defense Secretary David Brice and his aide Scott Pritchard hire to investigate a murder that they are attempting to blame on a Soviet mole is the person they are trying to frame and knows that Brice is the one actually guilty of the murder.

Video Games

 * Amateur Adventure Game example: the AGS adventure game features a freelance detective who
 * Ace Attorney had a lawyer patsy :.
 * Non-detective variation: In Metal Gear Solid 2 Sons of Liberty,.
 * In the third chapter of Limbo of the Lost, after being wrongfully accused of stealing souls, Briggs is accounted for by collector O'Negus, freed, and appointed detective by the mayor to determine who is actually stealing the souls.

Anime and Manga

 * In  of Magical Girl Lyrical Nanoha,  found herself in this role, as she eventually found out that the perp who was behind the killings of the case she was investigating was.
 * In Detective Conan, a case that had both Conan and Heiji working together in Osaka had

Western Animation

 * Scooby Doo featured this something like every second episode, and so did the movie.
 * Used in the two part Batman Beyond episode "The Call."  asks for Batman's help uncovering a traitor in the JLU. Guess who the traitor is?