Jury nullification is not illegal in the sense of being a crime a juror commits by voting to acquit, but the American legal system treats it as a violation of a juror’s duty and has built an entire preventive apparatus around stopping it. A juror cannot be punished for how they voted, and an acquittal reached through nullification is permanent. A juror who announces during deliberations that they refuse to follow the law can be removed from the jury, and a juror who lied during selection to get on the panel can be prosecuted for contempt or perjury.
The confusion over whether nullification is “illegal” comes from a real contradiction in the law. Jurors have the raw power to acquit against the evidence. They have no recognized right to do so. Everything that happens in a courtroom is designed to keep those two things from meeting.
Power Without a Right
The Supreme Court drew the line in 1895 in Sparf v. United States, holding that jurors have a duty to receive the law from the court and apply it as instructed. The Court acknowledged that a general verdict inevitably involves the jury deciding both law and fact, but said judges are under no obligation to tell jurors they can disregard the law.1Library of Congress. Sparf and Hansen v. United States, 156 U.S. 51 (1895)
The D.C. Circuit reinforced this in 1972 in United States v. Dougherty, holding that a defendant cannot raise jury nullification at trial and that judges need not inform jurors of the power.2Justia Law. United States v. Dougherty, 473 F.2d 1113 (D.C. Cir. 1972) The court recognized that nullification had existed throughout American history but concluded that keeping jurors uninformed about it was a deliberate design choice, allowing conscience to function as a rare safety valve without being advertised as an option.
So the raw power exists because no one can see inside a juror’s head. The right doesn’t exist because every formal rule points jurors toward obedience.
Why an Acquittal Based on Nullification Still Stands
The reason jurors cannot be punished for a nullifying verdict is the Fifth Amendment’s Double Jeopardy Clause. Once a jury returns “not guilty,” a judge cannot overturn it and the prosecution cannot appeal it. The Supreme Court has called this “the most fundamental rule in the history of double jeopardy jurisprudence,” reasoning that a second trial would let the government use its superior resources to grind an innocent person down into a conviction.3Constitution Annotated | Congress.gov | Library of Congress. Amdt5.3.6.1 Overview of Re-Prosecution After Acquittal
The protection holds even when the acquittal is plainly wrong. The Court has said that no balancing of public safety interests is permitted with respect to acquittals, “no matter how erroneous, no matter even if they were egregiously erroneous.”3Constitution Annotated | Congress.gov | Library of Congress. Amdt5.3.6.1 Overview of Re-Prosecution After Acquittal Because the verdict itself is unchallengeable, individual jurors cannot be penalized for their vote. Even if a juror later admitted openly that they ignored the law, the acquittal remains and the juror faces no punishment for the vote.
Jeopardy attaches the moment the jury is sworn. From that point, the government gets one shot, and any acquittal is permanent.
How Courts Stop Nullification Before a Verdict
Since nullification cannot be undone afterward, courts work to prevent it before and during trial. Three mechanisms do most of the work.
Jury Selection
During voir dire, prosecutors and judges routinely ask prospective jurors whether they can follow the law as instructed even if they personally disagree with it. A juror who says no, or who voices a moral objection to the statute at issue, is dismissed for cause and removed from the pool. This filters out people who are honest about their views. It does nothing about those who stay quiet, which is where the real legal risk later shows up.
Jury Instructions
Pattern jury instructions explicitly tell jurors to apply the law whether they agree with it or not. The Ninth Circuit’s model instruction, for example, tells jurors: “To the facts as you find them, you will apply the law as I give it to you, whether you agree with the law or not.”4Ninth Circuit District & Bankruptcy Courts. 1.1 Duty of Jury – Model Jury Instructions Similar language appears in every federal circuit and in state courts. Nullification is never mentioned. Under Sparf and Dougherty, judges are not required to disclose it.
What Attorneys Can and Cannot Say
Defense attorneys are prohibited from arguing for nullification. A lawyer cannot ask jurors to ignore the law, acquit out of sympathy, or reject a statute on moral grounds. A nullification pitch can trigger a mistrial, court sanctions, or discipline by the state bar. The person in the courtroom best positioned to explain nullification to jurors is the one person forbidden to do so.
Being Removed From the Jury Mid-Deliberation
The most direct consequence a juror can face for nullifying is removal while deliberations are still happening. Federal Rule of Criminal Procedure 23(b)(3) allows a court to excuse a juror for “good cause” after the jury retires and let the remaining eleven return a verdict.5Legal Information Institute. Federal Rules of Criminal Procedure Rule 23 – Jury or Nonjury Trial
The Second Circuit’s 1997 decision in United States v. Thomas is the leading case. The court held that a juror’s purposeful disregard of the law as set forth in the court’s instructions is grounds for dismissal, but added a strict safeguard: a juror may be removed for refusing to follow the law “only where the record is clear beyond doubt that the juror is not, in fact, simply unpersuaded by the prosecution’s case.”6Justia Law. United States v. Thomas, 116 F.3d 606 (2d Cir. 1997)
That standard matters. A juror who votes “not guilty” because they think the prosecution failed to prove its case is doing their job. A juror who announces that the law is unjust and declares they will not apply it is not. The line between the two can be blurry in practice. Judges rely on reports from other jurors or notes from the deliberation room, and they investigate cautiously, because removing a juror too readily can chill legitimate dissent and can be grounds for reversal on appeal.
When Nullification Does Become a Crime
The protections that shield a juror’s vote do not shield dishonesty during jury selection. Lying under oath in voir dire to conceal a bias or a plan to ignore the law can be prosecuted as criminal contempt or perjury.
The Supreme Court addressed this in Clark v. United States in 1933, upholding the contempt conviction of a juror who deliberately concealed information during questioning that would have struck her from the panel. The Court held that the offense is not the false swearing alone, but using it to gain acceptance as a juror and obstruct the course of justice.7Library of Congress. Clark v. United States, 289 U.S. 1 (1933)
Federal appeals courts have applied this principle repeatedly, treating a juror’s willingness to lie about a material fact as evidence of partiality that can support perjury or contempt charges. The practical point for anyone considering jury service with nullification in mind: if you are asked during voir dire whether you can follow the law as instructed and you say yes while intending to do the opposite, that false answer is itself a prosecutable act. The vote cannot be punished. The lie that got you onto the jury can be.
Civil Cases Work Differently
Everything above applies to criminal trials. In civil cases, judges can override a jury verdict that ignores the law. Judgment as a matter of law, historically called judgment notwithstanding the verdict, lets a judge set aside the verdict and enter judgment for the other side. Judges can also grant a new trial when a verdict runs clearly against the weight of the evidence. The Double Jeopardy Clause does not apply, and losing parties can appeal. Nullification, in the sense of a final unreviewable verdict against the law, only works in criminal cases.
Talking About Nullification Outside the Courtroom
The hostility to nullification inside the courtroom sometimes extends to advocacy outside it. In 2015, two men were arrested on the plaza outside a Denver courthouse for handing out pamphlets about jury nullification to passersby who might be prospective jurors, and they were charged with jury tampering under Colorado law. Other activists challenged the restriction on First Amendment grounds, and the Tenth Circuit weighed the government’s interest in preventing jury tampering against the right to engage in political speech on public property near a courthouse.8Justia Law. Verlo v. Martinez, No. 15-1319 (10th Cir. 2016)
Discussing nullification in general terms is protected speech. The closer that speech gets to an actual jury, whether through pamphlets at a courthouse entrance or an attorney’s closing argument, the more likely it is to draw legal consequences. A handful of states have moved the other direction, with laws or constitutional provisions that require courts to tell jurors they can judge both the facts and the application of the law. Those remain narrow exceptions, and even where they exist, what jurors are actually told varies.