What is jury nullification?

Jury nullification occurs when jurors return a not guilty verdict despite concluding that the prosecution proved its case, typically because they regard the law itself, or its application to this defendant, as unjust. It exists not because any statute permits it but because of two structural features: an acquittal cannot be appealed or overturned under double jeopardy protections, and jurors cannot be punished for their verdict, a principle established in England by Bushel's Case in 1670. The combination makes the acquittal final regardless of reasoning.

Its history cuts in several directions. Colonial juries used it in the 1735 Zenger seditious libel trial and later against the Fugitive Slave Act, and twentieth-century juries used it against Prohibition prosecutions, which are the examples usually cited approvingly. It was also used by all-white Southern juries to acquit defendants in racial violence cases, which is the counterexample that makes blanket enthusiasm difficult. The same mechanism that permits mercy permits impunity, and it operates without accountability in either direction.

Courts have consistently declined to inform juries of the power. Sparf v. United States in 1895 held that judges need not instruct juries about it, and federal courts have upheld removing jurors who state an intention to disregard the law and have permitted restrictions on attorneys arguing for nullification. Standard jury instructions direct jurors to apply the law as given. Advocacy organizations distribute information about it, and courts have split on whether such leafleting near courthouses constitutes jury tampering or protected speech. The practical situation is that the power exists, cannot be eliminated, and is deliberately not advertised by the institutions that rely on juries.