In a jury trial, a Chewbacca defense is a legal strategy in which a criminal defense lawyer tries to confuse the jury rather than refute the case of the prosecutor. It is an intentional distraction or obfuscation.
As a Chewbacca defense distracts and misleads, it is an example of a red herring. It is also an example of an irrelevant conclusion, a type of informal fallacy in which one making an argument fails to address the issue in question. Often an opposing counsel can legally object to such arguments by declaring them irrelevant, character evidence, or argumentative.
The name "Chewbacca defense" comes from "Chef Aid", an episode of the American animated series South Park. The episode, which premiered on October 7, 1998, satirizes the O. J. Simpson murder trial, particularly attorney Johnnie Cochran's closing argument for the defense. In the episode, a fictionalized version of Cochran bases his argument on a false premise about the 1983 film Return of the Jedi. He asks the jury why a Wookiee like Chewbacca would want to live on Endor with the much smaller Ewoks when "it does not make sense". He argues that if Chewbacca living on Endor does not make sense—and if even mentioning Chewbacca in the case does not make sense—then the jury must acquit.
In the Simpson murder trial, the real Johnnie Cochran tried to convince jurors that a glove found at the crime scene, alleged to have been left by the killer, could not be Simpson's because it did not appear to fit Simpson's hand. Because the prosecution relied on the glove as evidence of Simpson's presence at the scene, Cochran argued that the lack of fit proved Simpson's innocence: "It makes no sense; it doesn't fit; if it doesn't fit, you must acquit." "If it doesn't fit, you must acquit" was a refrain that Cochran also used in response to other points of the case.
Origin
In the episode, the character of Chef contacts a "major record company" executive, seeking to have his name credited as the composer of a fictional Alanis Morissette hit called "Stinky Britches". Chef's claim is substantiated by a 20‑year-old recording of Chef performing the song.
The record company refuses and hires Johnnie Cochran, who files a lawsuit against Chef for harassment. In court, Cochran resorts to his "famous" Chewbacca defense, which he "used during the Simpson trial," according to Chef's lawyer, Gerald Broflovski. Although Broflovski uses logic, reasoning, and the fact that Chef properly copyrighted his work, Cochran counters with the following:
This statement is a parody of Cochran's closing arguments in the O. J. Simpson murder case, where he said to the jury, "If it doesn't fit, you must acquit" in reference to a courtroom demonstration in which Simpson appeared unable to fit a pair of bloody leather gloves found at the murder scene over the medical gloves he was wearing.
In the episode, Cochran's defense is successful. The jury finds Chef guilty of "harassing a major record label", after which the judge sets his punishment as either a $2 million fine to be paid within 24 hours or, failing that, four years in prison (the judge initially sentences him to eight million years before being corrected by a court officer).
Ultimately, a "Chef Aid" benefit concert is organized to raise money for Chef to hire Cochran for his own lawsuit against the record company. At the concert, Cochran has a change of heart and offers to represent Chef pro bono. He again successfully uses the Chewbacca defense, this time to defeat the record company and force them to acknowledge Chef's authorship of their song. In the second use of the Chewbacca defense, he ends by taking out a monkey puppet and shouting, "Here, look at the monkey. Look at the silly monkey!" causing a juror's head to explode.
Use
The Associated Press obituary for Cochran mentioned the Chewbacca defense parody as one of the ways in which the attorney had entered pop culture.