Luigi Mangione, the man accused of killing UnitedHealthcare CEO Brian Thompson, pleaded guilty Friday to two federal counts of stalking resulting in death. Mangione admitted in court to shooting Thompson in Manhattan.

“I shot Mr. Thompson in Manhattan and he died,” Mangione stated, as reported by The Associated Press. “I knew what I was doing was illegal.”

This plea casts doubt on the upcoming New York state murder trial, which was scheduled to begin September 8. Mangione's attorney has filed a motion in New York state court arguing that double jeopardy protections should lead to the dismissal of the state case. Mangione has previously argued that proceeding with both state and federal cases violates his rights.

The federal trial for Mangione had been scheduled for January 5, 2027, where he faced a potential life sentence. Sentencing on the two federal counts is now set for December 18.

Thompson, CEO of UnitedHealthcare, was killed in December 2024 as he walked outside a New York City hotel where his company was holding an annual conference. Mangione was captured five days later in Pennsylvania. Authorities reported finding a backpack containing a firearm, a homemade silencer, and a notebook referencing the crime, though some evidence was later barred from the state trial due to processing errors.

Before U.S. District Judge Margaret Garnett, Mangione indicated that his actions stemmed from years of debilitating back pain and struggles with the insurance industry. He reportedly posed as an investor via email to learn the location of the UnitedHealthcare conference and then traveled to New York.

Legal experts suggest that Mangione's explicit confession in court, detailing his knowledge that his actions were illegal, could significantly influence the state case. "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," New York Law School professor Anna Cominsky told HuffPost. "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."

The defense has estimated that Mangione could receive a federal sentence between 24 years and four months and 30 years and five months. The killing of Thompson prompted widespread discussion about the challenges of accessing healthcare and insurance in the United States. Supporters of Mangione have attended his court appearances, some referencing the video game character Luigi.

Mangione's family and friends told The New York Times that they had lost touch with him in the months leading up to the killing, expressing bewilderment at his transformation. In college, Mangione reportedly experienced health issues that affected his academic performance, and later suffered a back injury in Hawaii.

Thompson's family released a statement calling the plea “an important step toward justice for Brian and for our family.” They expressed gratitude that the federal justice system has held the person responsible accountable and look to the court to ensure sentencing reflects the crime's severity.

U.S. Attorney Jamie McDonald stated that Mangione's crime was “deliberate, calculated and premeditated,” and that violence is not a legitimate tool for promoting social or political messages.

Mangione, the suspect in the killing of UnitedHealthcare CEO Brian Thompson, arrives by helicopter from Pennsylvania in December 2024.