What Is Jury Nullification? A Plain Guide

Jury nullification is one of the most debated ideas in criminal law. It happens when a jury finds a defendant not guilty even though the evidence shows the defendant broke the law, because the jurors believe the law itself, or its use in that case, is unjust.

It is not a formal rule written into statutes, and judges do not invite it. Yet it exists because of how the jury system is built. Here is a plain explanation.

How nullification is possible

In criminal trials in the United States, a jury's verdict of not guilty is generally final. The Double Jeopardy Clause of the Fifth Amendment prevents the government from trying a person again for the same offense after an acquittal.

Jurors also are not required to explain their reasoning, and they cannot be punished for the verdict they reach. Together, these features mean a jury has the practical power to acquit for any reason, including disagreement with the law. That power is what people mean by nullification.

A long history

The idea has deep roots in English and American legal history. In 1670, jurors in the trial of William Penn in London refused to convict him for unlawful assembly. Some were jailed for their verdict, and the decision in Bushel's Case that followed established that jurors could not be punished for the verdict they returned.

In colonial New York in 1735, printer John Peter Zenger was acquitted of seditious libel after his lawyer, Andrew Hamilton, urged the jury to consider whether what Zenger printed was true. The case is often cited as an early landmark for press freedom.

In the decades before the Civil War, some juries in northern states refused to convict people charged under the Fugitive Slave Act of 1850. Supporters of nullification often point to these examples as moments when juries acted as a check on unjust laws.

How courts treat it today

Courts recognize that juries have the power to acquit, but they do not recognize a right to be told about it. In Sparf v. United States, decided in 1895, the Supreme Court held that federal judges are not required to instruct juries that they may disregard the law.

Today, judges instruct jurors to apply the law as the court explains it. Defense lawyers are generally not permitted to argue openly for nullification. Some federal appeals courts have also held that a judge may remove a juror who clearly intends to ignore the law during deliberations.

Why it remains controversial

Supporters see nullification as a safeguard. They argue that ordinary citizens serve as the conscience of the community and can protect defendants from laws that are outdated, harsh or applied unfairly.

Critics see real danger. If juries can ignore the law in a sympathetic case, they can also ignore it for prejudiced reasons. History includes troubling examples of juries in the segregation era acquitting defendants accused of violence against Black Americans despite strong evidence. Critics argue that equal treatment under the law depends on juries following it.

What jurors should know

Jurors take an oath to decide the case according to the evidence and the law as instructed by the judge. Courts take that oath seriously, and questions during jury selection may explore whether a potential juror can follow the law.

Anyone with questions about jury service or a specific case should consult a qualified attorney or the court itself. This guide explains a concept and is not legal advice.

The bottom line

Jury nullification is less a rule than a consequence of how the jury system protects acquittals. It has been praised as a check on injustice and criticized as a threat to equal justice. Understanding it helps explain both the power and the responsibility that come with sitting on a jury.