Patterson v. Alabama
Jury nullification takes place when a jury acquits a defendant even though the prosecution has proven the defendant's guilt beyond all reasonable doubt. The jury acquits the defendant because they disagree with the law whereby he or she is charged, and their acquittal serves as a form of protest.
The idea of jury nullification originated in England and gained popularity among rebellious American colonists, who used it as a means of registering their dissatisfaction with British rule. In the years leading up to the Civil War, jury nullification became popular with Abolitionists, who likewise used it to protest what they saw as an unjust system: the Fugitive Slave Law, which required the return of runaway slaves. During the late 1800s and early 1900s, white Southern juries, by refusing to convict white men guilty of killing blacks, used jury nullification for less idealistic purposes.
Despite its long and varied past, jury nullification did not gain popular attention until 3 October 1995, when a mostly African American jury in the O. J. Simpson murder case issued a "not guilty" verdict, an act which many saw as an attempt to address past racial injustices.