Jury Nullification

Juries have the implicit power to acquit defendants despite evidence and judicial instructions to the contrary. This power, called jury nullification, is embedded in the jury’s right to return a verdict by its own moral compass and has historically permitted sympathetic juries to acquit those whom the jurors perceive as legally guilty but morally upright. The criminal jury’s power to deliver a verdict counter to both the law and evidence resides in the fact that a general verdict requires no explanation by the jury. Some citizens’ groups and some legal scholars believe that the jury not only should have the ability to nullify but also the right to be explicitly informed of this right. However, the majority of the legal community, with near unanimity among sitting judges, prefers the status quo—juries are not informed of this nullification power but are free to exercise it without prompting when the jury believes that a guilty verdict clearly violates community sentiment. Research has shown that juries informed of their nullification power are more likely to consider extralegal factors and may be more prone to be persuaded by emotional biases.

A Short History of Jury Nullification

Judges uniformly instruct the jury that they must apply the law as provided by the court. However, jurors traditionally have been able to act as the “conscience of the community,” a long-standing role that implicitly enabled juries to return verdicts that fly in the face of the proffered law. Depending on one’s point of view, this much-disputed power of the jury has served the interest of justice or has led to injustice and chaos in the legal system.

Academic Writing, Editing, Proofreading, And Problem Solving Services

Get 10% OFF with 24START discount code

Juries in England historically had been constrained by the King. The jury’s power to deliver an unfettered verdict was essentially nonexistent, although there is evidence that the English jury, in its various guises, refused to convict defendants who were unfairly charged or for whom the sentence was wildly disproportionate to the crime. However, juries did this at great peril. The Crown had the means and the will to punish the jury for verdicts of which it disapproved. Juries could be incarcerated, without food or drink, until they returned a suitable verdict. Indeed, their very fortunes and families were put at risk.

In 1670, this state of affairs began to change. A seminal case, known as Bushell (the name of the jury foreman), prohibited the Crown from punishing the jury for verdicts deemed unlawful or rebellious. Bushell involved a trial in which the famous Quakers, William Penn and William Mead, were charged with fomenting revolution by preaching in the streets. Against all expectations, the jury returned a not-guilty verdict and maintained their stance against the King’s fearsome intimidation. The result was revolutionary: an independent jury.

Juries in the American colonies often served as a buffer between colonists and unpopular British laws. Famously, an 18th-century jury acquitted the printer John Peter Zenger of sedition when he had certainly violated the local law prohibiting criticism aimed at representatives (New York’s Mayor) of the Crown. Colonial juries routinely acquitted smugglers (most notably, John Hancock) and others who defied unpopular laws. Jury power was rather untrammeled from the Revolution until the middle of the 19th century. And in the absence of a highly professional legal community, juries often decided on the basis of their own notions of what was just, the law notwithstanding. The proponents of the jury’s right to nullify the law suggest that juries have historically had that power and right.

It is clear that the nullification power was extant during the early days of the Republic. It was perhaps not as ubiquitous as presumed. In very few colonies was the nullification power explicit, and according to one scholar, there are indicators that there was no such right for much of the colonial era in Georgia, Maryland, and Massachusetts.

Some historical indications suggest that the jury’s right to nullify moved only in one direction—toward mercy, but some scholars disagree. This power did not include the power to legislate new law. American juries that stood against the oppressive power of the British King were held in high esteem, as were the fiercely independent agrarian juries in the early part of the 19th century. It is no coincidence that concerns about the power of the jury began to surface primarily in the middle of the century, when immigration from Europe increased at a remarkable rate. By the 1850s, powerful legal figures, such as Justice Joseph Story, were arguing vigorously against an unfettered jury.

Despite the attempts of a number of state legislatures to sustain jury power, an increasingly professional legal community, through a cascading series of appellate cases, began to rein in the power of jurors to decide cases with little or no concern for the relevant law. In 1895, the U.S. Supreme Court offered its only opinion on the jury’s nullification power. In Sparf and Hansen v. United States, the Court proscribed the jury’s explicit power and authority by indicating that the jury’s obligation was to follow the law as received from the Court and to apply that law to the facts. Nevertheless, the issue of nullification resurfaced at various times, almost always during periods of social and political unrest. Some Northern juries refused to convict violators of the Fugitive Slave Act in the 1850s. Juries refused to convict labor organizers of conspiracies during the 1890s. The Eighteenth Amendment, known as the Volstead Act, which prohibited both the manufacture and the consumption of intoxicating liquor, was widely violated by both the public and the criminals who illegally imported or manufactured the banned substances. Citizens who violated this act during the period known as Prohibition often walked out of the courtroom free men because juries were opposed to what they perceived as unwelcome government interference in their daily life and pleasures. In the tumultuous 1970s, juries sometimes set free those who had illegally avoided the draft during the later, more unpopular stages of the Vietnam War, and other juries refused to convict physicians for euthanizing the terminally ill. Jury behavior in these circumstances either made the laws moot or convinced prosecutors not to bring cases that they would surely lose.

Without question, the jury’s nullification power also has a dark side, most notably when (mostly) Southern juries from the Reconstruction onward acquitted transparently guilty Whites for depredations committed on Black citizens. This disturbing side of nullification (“jury vilification”) was seen when juries returned verdicts that reflected prejudiced or bigoted community standards and violated the benign standard of nullification proponents that such verdicts should be merciful rather than vindictive. In fact, one nullification scholar notes that the difference between vengeance and mercy is an unprincipled one and that, while nullification may have had some legal basis in colonial days, it is now a legal anachronism. Modern proponents of jury power argue that the jury has both the right and the power to judge both the defendant and the law. It is an obvious understatement to say that the right of the jury to nullify has more support among legal academics than among judges.

Some legal scholars and jury activists argue that judges and courts are actively attempting to constrain the jury’s unfettered right to return a verdict according to its own views. One scholar points to the antinullification section appended to the California Jury Instructions. Proponents want judges to inform jurors directly that they can exercise their right to nullify. Indeed, much of the empirical research on nullification has focused on the effects of providing just such an instruction to the jury. One practicing attorney eloquently argues that defense attorneys should aggressively seek nullification in cases where their technically guilty clients are morally blameless. Proponents believe that nullifying juries inform the legal process and militate against unjust laws. Furthermore, the pronullification argument contends that research shows that laypeople are more sophisticated than the courts assume and that anarchy emanates not from jury disobedience but when laws are in conflict with community sentiment.

Jury Research and Nullification Instructions

The modern debate as to the limits of the jury’s power was most clearly limned in United States v. Dougherty (1973), in which a 2:1 majority rejected a defense request that the nullification instruction be permitted in this trial of antiwar activists. Judge Harold Leventhal, writing for the majority of the D.C. Court of Appeals, while noting that the pages of history abound with shining examples of juries that refused to convict virtuous defendants, nevertheless suggested that if juries were given explicit nullification instructions, their behavior would be anarchic. Such an instruction would result in “chaos” because the verdict would not be predicated on the law. Furthermore, an explicit declaration of the jury’s power to nullify would, in Judge Leventhal’s view, require the jury to “fashion” the law. Judge Leventhal argued that without explicit knowledge of nullification, juries would use their implicit power more carefully and judiciously, not chaotically.

A number of researchers have explored the impact on verdicts of jury instructions that include a nullification clause. These are laboratory-based studies of varying levels of similarity to legal processes. Results suggest that juries that received nullification instructions spent less time deliberating the evidence and focused more on defendant characteristics, attributions, and personal experiences. Jurors in receipt of nullification instructions were more likely to take account of the extralegal factors of race, gender, and social class. One researcher reported that mock jurors were significantly less likely to return a guilty verdict for an individual accused of murder in a context where the act might be characterized as euthanasia. When in receipt of nullification instructions and when the act was committed out of compassion (such as disconnecting a respirator or increasing a morphine drip), the jury verdicts were the same as those returned by juries given standard instructions. Note that much may depend on the nature of the nullification instructions, which are usually appended to the standard instructions. Thus, what we see in many studies is a fairly circumscribed use of jury power, as Judge Leventhal had suggested.

However, researchers have reexamined this “chaos” hypothesis by examining situations that evoke jurors’ emotional biases. These biases are evoked by information that strongly affects jurors’ emotions (e.g., gruesome crime-scene photos) but that implies nothing directly about the guilt or innocence of the defendant. In several experiments, researchers have found that nullification instructions can indeed change and intensify jurors’ responses to such emotionally biasing information. For example, in one study, information about the victim of a crime affected jurors’ emotions so that they were much more upset at the alleged murder of an upright, admirable person than that of a less-worthy citizen. When mock jurors were given standard jury instructions (which tell them that they must follow the law as it is explained by the trial judge), these emotional reactions did not affect their verdicts.

In another research example, mock jurors heard one of two versions of a trial in which a physician was charged with murder. In the first version, the physician had euthanized a patient he knew (to relieve suffering); in the second version, the physician was charged with murdering the patient for financial gain. In other words, while the euthanatizing procedure was the same—increasing a drug dose beyond the recommended dosage, the motive for that act was different in the two circumstances. When jurors were given standard instructions, the apparent motive of the surgeon had no effect. Jurors found the defendant guilty irrespective of the motive. However, when the jury was in receipt of nullification instructions, a surgeon who increased the drug dose to relieve suffering was less likely to receive a guilty verdict. Nullification instructions induced jurors to attend to emotionally biasing information (e.g., how sympathetically the victim was portrayed). Proponents of jury nullification would likely argue that these results sustain their view that juries will use their right to nullify judiciously. Those opposed to jury nullification would suggest that the law should determine trial outcomes, not the whims, however well meant, of the jurors.


  1. Brown, D. K. (1997). Jury nullification within the rule of law. Minnesota Law Review, 81, 1149-1200.
  2. Conrad, C. S. (1998). Jury nullification: The evolution of a doctrine. Durham, NC: Carolina Academic Press.
  3. Finkel, N. J. (1995). Commonsense justice. Cambridge, MA: Harvard University Press.
  4. Horowitz, I., Kerr, N. Park, E. S., & Gockel, C. (2006). Chaos in the courtroom reconsidered: Emotional bias and juror nullification. Law and Human Behavior, 30, 163-181.
  5. Horowitz, I. A., & Willging, T. E. (1991). Changing views of jury power: The nullification debate, 1787-1988. Law and Human Behavior, 15(2), 165-182.
  6. Howe, M. (1939). Juries as judge of criminal law. Harvard Law Review, 52, 582-616.
  7. Sparf and Hansen v. United States, 156 U.S. 51 (1895).
  8. John, R. R. (1997). License to nullify: The democratic and constitutional deficiencies of authorized jury lawmaking. Yale Law Review, 106, 2563-2597.
  9. United States v. Dougherty, 473 F.2d 1113 (1973).

Return to the overview of Trial Consulting in Forensic Psychology.