Luigi Mangione appears in Manhattan Supreme Court in New York on December 23 to face murder charges in the shooting of UnitedHealthcare CEO Brian Thompson.
CNN  — 

Luigi Mangione, the 26-year-old accused of killing UnitedHealthcare CEO Brian Thompson, has received more public support than is typical for a man charged with first-degree murder.

Outside court in New York last month, people held signs saying “Free Luigi” and protested the profit-focused health care insurance industry. Other supporters wore a green hat like the one worn by the video game character Luigi. His attorney said he’s received some emails from people offering to help pay for his legal bills. And there was extended applause at the mention of his name in a comedy bit on “Saturday Night Live.”

Add it all up, and the positive public opinion for Mangione raises the remote possibility of a legal result in the gray area of American law: Jury nullification.

Jury nullification is the term for when a jury declines to convict a defendant despite overwhelming evidence of guilt. This can be a form of civil disobedience, a political statement against a specific law, or a show of empathy and support to the defendant.

“It’s not a legal defense sanctioned under the law,” said Cheryl Bader, associate professor of law at Fordham School of Law. “It’s a reaction by the jury to a legal result that they feel would be so unjust or morally wrong that they refuse to impose it, despite what the law says.”

Over the centuries, American juries have nullified cases related to controversial topics like fugitive slave laws, Prohibition and, in recent decades, the war on drugs.

Yet nullification occupies an odd position in the legal system. The defense is not allowed to encourage a jury to nullify a case, and the jury is required to follow the evidence and the law. But what happens in the deliberation room is secret, and there’s no way to appeal if a jury decides to acquit.

Juries who nullify cases don’t think about it in those terms, said Clay S. Conrad, author of “Jury Nullification: The Evolution of a Doctrine.”

“The way jury nullification tends to work is not that the jury says, ‘Not guilty, because your law sucks.’ It’s not that simple,” he told CNN. “Usually when a jury nullifies, what they do is give a lot of weight to weak evidence because it gives them an excuse to do what they want to do anyway, which is acquit.”

That provides a slim opening for a defendant like Mangione given the significant allegations he killed Thompson. When Mangione was arrested in Pennsylvania, investigators allegedly found on him the fake ID used by the suspect, the gun used in the shooting and a handwritten “claim of responsibility,” authorities have said.

Prosecutors have argued Mangione expressed hostility toward the health insurance industry and wealthy executives, a relatively mainstream position in modern American politics. He has pleaded not guilty to state murder and terror charges, but has yet to enter a plea on federal murder charges.

Legal experts said his defense could try to tap into the jury’s own frustration with the for-profit insurance industry, get them to sympathize with him and nullify the cases.

Protestors hold signs outside of Manhattan Criminal Court on December 23 in New York City.

“I wonder whether a jury, whether they get impaneled, really buys his message, hates health care so much that they say, ‘Hey, look, we saw what you did. We know what you did, but we’ll excuse it,’” CNN Legal Analyst Joey Jackson said last month. “You never can tell.”

“It would not surprise me at all if one or more people get onto the jury that support him,” Conrad said.

Still, the jury selection process, known as voir dire, is designed to weed out people who are unwilling to follow the evidence and the law. Bader said she’s skeptical a jury would nullify here because the allegations are so serious.

“This is not a case of (Mangione) like throwing blood on this guy as he’s walking into the convention,” Bader said, referring to the scene of the shooting outside an investors’ conference in Midtown Manhattan. “If the jury finds that there’s evidence that he ended this man’s life in cold blood, I don’t see the result being an acquittal because of anger toward the health insurance system.”

The long history of jury nullification

The idea of jury nullification dates back at least 800 years to the Magna Carta, which established the right to a trial by a jury of peers, Conrad explained.

“There’s a long, complicated history of juries intervening,” he told CNN.

Examples abound in the history of the US. In the Revolutionary Era, some colonial American juries declined to convict in a protest of British power. “It is not only his right but his Duty in that Case to find the Verdict according to his own best Understanding, Judgment and Conscience, tho in Direct opposition to the Direction of the Court,” President John Adams wrote in 1771.

The practice can strike against the rule of law in contradictory ways. In the lead-up to the Civil War, many juries in the North refused to convict people accused of helping slaves escape. However, during the Jim Crow era, some juries in the South declined to convict White people who were accused of killing Black people, most infamously for the murder of Emmett Till.

“It can also be used as a disregard for the rule of law without a just purpose,” Bader said.

Because of double jeopardy, a defendant who is acquitted cannot be tried again for the same crime. If even one juror refuses to convict, that leads to a hung jury and mistrial, and the prosecution has to decide if they want to bring the case again.

In recent decades, jury nullification has reared its head in cases that touched on hot-button social issues. For example, Dr. Jack Kevorkian, known as “Dr. Death,” admitted that he helped multiple people die by suicide, yet he was acquitted three times by a jury on charges of assisted suicide. He was ultimately convicted of second-degree murder in 1999.

Juries acquitted Dr. Jack Kevorkian, aka "Dr. Death," several times before he was convicted of second-degree murder on March 26, 1999, in Pontiac, Michigan.

Juries also have acquitted some abused women who killed or attacked their husbands, such as Francine Hughes, leading to a wider recognition of what’s known as battered woman syndrome.

“Juries recognized that before the law did,” Conrad said. “The law is slow to change. Sometimes society changes much more quickly than the law, and that is when jury nullification should come in … We don’t need to have 18th-century law governing 21st-century behavior, and the jury can say so.”

The challenges of nullification

Because jury deliberations are secret, it’s often not possible to determine why a jury came to a certain decision.

Sometimes members of the jury speak publicly about their deliberations, but if not, determining what is “nullification” and what is a common acquittal or hung jury is not always so clear.

The quasi-legal status of nullification leads to a sort-of “don’t ask, don’t tell” position in which neither the defense nor the jury mentions nullification out loud.

Even outside court, civilian advocates can face legal trouble for pushing nullification. In 2017, a man named Michael Picard was arrested for handing out flyers saying “Google Jury Nullification” near a New York courthouse, violating a state law that banned protests about a trial within 200 feet of a courthouse.

The American Civil Liberties Union sued on Picard’s behalf, citing his First Amendment rights. The US District Court ruled in 2020 the state law was unconstitutional, although the US Court of Appeals then vacated that decision in 2022.

“Whatever you may think about jury nullification, it shouldn’t be a secret, and talking about it in public shouldn’t be a crime,” Picard wrote in 2019 for the ACLU.

Jury nullification was a notable discussion point in the unusual 2022 trial of Darrell Brooks, the man accused of driving a car through a Christmas parade in Waukesha, Wisconsin, and killing six people.

Brooks represented himself at trial and often disrupted court proceedings with defiant and outlandish behavior and legal arguments. He challenged the court’s jurisdiction, insisted “Darrell Brooks” was not his name and – despite repeated warnings from the judge – advised the jury they had the power to nullify the case.

“You should be informed that you have the power to nullify any law that you don’t agree with,” Brooks said in closing arguments. The prosecution objected to that line, and the judge sustained the objection and struck it from the record.

Darrell Brooks attempted to argue for jury nullification at his 2022 intentional homicide trial despite the judge's warnings.

The tactic did not work. The jury convicted Brooks of six counts of first-degree intentional homicide, and he was sentenced to life in prison.

For Mangione, in a state court hearing December 23, his attorney Karen Friedman Agnifilo said she was concerned about her client’s right to a fair trial because of prejudicial statements from some officials.

Judge Gregory Carro sought to assure her in his response, with a clear focus on that all-important panel who will decide his fate.

“I can guarantee you the defendant will receive a fair trial,” he said. “We will carefully select a jury.”