Luigi Mangione, the accused killer of a UnitedHealthcare CEO, pleaded guilty Friday to two federal counts of stalking resulting in death, standing up in court to speak publicly about his actions for the first time.
“I shot Mr. Thompson in Manhattan and he died,” Mangione said, per The Associated Press. “I knew what I was doing was illegal.”
The plea now throws his New York state murder trial, scheduled to begin Sept. 8, into doubt. Attorney Karen Agnifilo announced immediately after the hearing that her team filed a motion in New York state court arguing that double jeopardy protections should allow the state case to be dismissed.
Generally, a person cannot be charged twice for the same act, although legal experts say determining which charges are duplicative can be quite complicated.
Mangione has alleged that allowing both the state and federal cases against him to proceed violates his rights, blurting out in court earlier this year that it was “double jeopardy by any common-sense definition.”
The federal trial had been scheduled to begin Jan. 5, 2027, with Mangione facing life behind bars.
Now, he will face sentencing on the two counts on Dec. 18.
The 28-year-old is accused of shooting and killing CEO Brian Thompson in a brazen act of violence on a New York City street in December 2024. Thompson had been walking outside the hotel where his company was set to hold an annual conference.
His death sparked a massive search, leading to Mangione’s capture five days later at a Pennsylvania McDonald’s where he was having breakfast. Police say they found a backpack full of evidence — including flash drives, a firearm, a homemade silencer and a red notebook supposedly referencing the crime — although errors in processing prompted New York Supreme Court Judge Gregory Carro to bar certain items from the state trial.
Members of Thompson’s family appeared in federal court on Friday to witness the plea, CNN reported, noting that they became overwhelmed with emotion as the proceedings went on.
Mangione stated before U.S. District Judge Margaret Garnett that he set his plan in motion after enduring years of debilitating back pain and battling the insurance industry. He posed as an investor in an email to learn the location of UnitedHealthcare’s annual conference and traveled to New York.
The details he confessed in court — not just that he traveled to New York but that he shot Thompson knowing what he did was illegal — could have an impact on the state case, New York Law School professor Anna Cominsky told JS.
“Certainly, the defense has been thinking about how what he said in court today and what he did is going to affect the state case, 100%,” Cominsky said.
“They have thought long and hard about what’s the best way to handle the case, and have counseled their client with respect to that,” she said. “This is an extremely thoughtful way to be handling these cases, because I’m of the opinion that they do have a very strong argument now with respect to double jeopardy.”
In their petition to dismiss the state case, the defense estimated that Mangione was likely to receive a federal sentence ranging between 24 years and four months and 30 years and five months.
The CEO’s killing sparked a nationwide discussion on the difficulty of seeking healthcare and healthcare coverage in America. Supporters of Mangione have turned out at all of his appearances in state and federal court, waving signs and donning “Mario Bros.”-themed apparel, referencing the classic video game that features a Luigi character.
“Like the thousands of people who have reached out since this tragedy to share their own experiences, he believed that the system had failed him and destroyed his life,” Agnifilo said of her client.
“He’s been treated differently from every other defendant charged with this offense in New York, however, thankfully, New York law does not allow this,” she said.
Mangione’s extradition from Pennsylvania to New York inspired then-New York Mayor Eric Adams to stage an elaborate, made-for-TV perp walk. News cameras followed Mangione, flanked by heavily armed law enforcement officers, as he walked from a helicopter to a motorcade waiting to take him to the federal prison in the city, where he has been held ever since.
Michael Nagle/Bloomberg via Getty Images
In college, Mangione appeared to experience health problems like brain fog and spotty vision that began to affect his academic performance at the University of Pennsylvania, according to reporting by The New York Times. Reddit posts linked to Mangione show how he sought answers for his various ailments. After graduating with a master’s degree in computer science, Mangione moved to Hawaii, where he reportedly injured his back during a surfing lesson, setting him down a darker path as everyday movements became difficult.
Mangione’s family and friends told the Times they lost touch with him in the months leading up to Thompson’s killing, and they expressed bewilderment at his transformation.
Thompson’s family called the plea “an important step toward justice for Brian and for our family.”
“While nothing will ease the pain of losing him, we are grateful that the federal justice system has held the person responsible for this heinous act accountable. Now we look to the court to ensure that sentencing reflects the severity of this crime,” the Thompson family said in a statement.
U.S. Attorney Jamie McDonald told reporters outside the courthouse that Mangione’s crime was “deliberate, calculated and premeditated.”
“Any person who celebrates, encourages or excuses actions like these is fundamentally wrong,” McDonald said. “Mangione attempted to send a public message through violence. But the message that emerges today is very different. Violence is not a legitimate instrument to promote any political or social message.”

