Luigi Mangione appears at an evidence suppression hearing at Manhattan Supreme Court on May 18, 2026 in New York City. Jeenah Moon | Getty ImagesLuigi Mangione pleaded guilty Friday in New York federal court to stalking that led to the killing of UnitedHealthcare CEO Brian Thompson on a midtown Manhattan street in December 2024.Mangione's lawyers immediately afterward filed a motion in New York state court saying that charges of murder and other counts in that court for Thompson's slaying should be tossed out under the state's double jeopardy law.Mangione said Friday in Manhattan U.S. District Court that he traveled to New York with the intention of killing Thompson after reaching out to UnitedHealthcare and pretending to be an investor ahead of a conference at a Manhattan hotel."I shot Mr. Thompson in Manhattan, and he died," Mangione said, according to MS NOW. "I knew what I was doing was illegal." Thompson's company, which is a division of UnitedHealth Group, is the largest provider of health insurance in the United States.Mangione, who also said he was motivated after suffering years of pain from a broken back, faces a possible maximum sentence of life in prison. Sentencing is scheduled for Dec. 18. Manhattan U.S. Attorney Jamie McDonald said he will seek a sentence of life for the charges of interstate stalking resulting in Thompson's death, and use of electronic communications for the purpose of stalking.Mangione's plea came weeks before jury selection is scheduled to start for his Manhattan Supreme Court trial on a charge of murdering Thompson.It is not clear if that trial will happen, given defense attorneys' new motion asking a judge to toss the state charges because of Friday's plea in federal court. Double jeopardy bars prosecuting a defendant twice for the same conduct.The Manhattan District Attorney's Office could argue in response to Mangione's double jeopardy argument that its case against him is not directly related to the same conduct for which he was charged in federal court.McDonald and Amanda Houle, chief of the office's Criminal Division, were sitting in the front row of court next to Thompson's widow and family during Friday's plea hearing, MS NOW reported. United Healthcare executives sat in the row behind them.After a court hearing in February, Mangione said out loud, "One plus one is two.""Double jeopardy by any common-sense definition," he said.This is breaking news. Please refresh for updates.