NEW YORK — Luigi Mangione pleaded guilty in Manhattan federal court Friday to two counts of stalking that resulted in the death of UnitedHealthcare Chief Executive Brian Thompson, admitting in his own words that he shot Thompson outside a Midtown hotel in December 2024 and canceling a federal trial that had been set for January.

The plea, entered without a bargain, hands prosecutors a conviction that carries a maximum sentence of life in prison and clears the way for U.S. District Judge Margaret Garnett to sentence Mangione on Dec. 18. It also opens a legal fight over whether the Manhattan district attorney can still put him on trial for murder in September, three weeks from now, or whether New York's double-jeopardy statute will shut that case down.

In the courtroom

Mangione, 28, entered the courtroom in beige prison clothing with his feet shackled and his hands behind his back. Thompson's family sat in the front row behind the prosecution. Defense attorney Karen Friedman Agnifilo told Judge Garnett shortly after 11 a.m. that her client was "prepared to plead guilty to the indictment at this time." Mangione answered the judge's competency questions tersely, then read a statement recounting years of severe back pain, frustration with the health-insurance system, and his decision to travel to New York carrying a 3D-printed pistol, a silencer and a loaded magazine.

"On the morning of December 4, 2024, I shot Mr. Thompson in Manhattan and he died," Mangione told the court. "When I did so, I understood that my actions would place him in fear of death or serious bodily injury. I knew what I was doing was illegal."

No plea agreement

Federal prosecutors made clear the plea was unilateral. U.S. Attorney Jamie McDonald said afterward that "our office does not have a plea agreement with him" and that "we are free to seek the maximum penalty under the law." Two of the four original federal counts — including a firearm-murder charge that carried the death penalty — were dismissed earlier this year, leaving the two stalking counts Mangione admitted Friday. The BBC reported prosecutors have recommended 24 to 30 years in prison; Garnett is not bound by that range. Mangione must serve at least 85 percent of any sentence, the judge told him, because there is no parole in the federal system.

Prosecutors then reviewed the evidence they had been prepared to introduce at trial: surveillance video of the shooting and of Mangione fleeing on a bicycle, the pistol and shell casings recovered at his Dec. 9, 2024, arrest at a McDonald's in Altoona, Pa., DNA at the crime scene, and notebook entries expressing his desire to kill a health-care executive. Police said the ammunition was inscribed with the words "delay," "deny" and "depose" — a phrase used to describe how insurers avoid paying claims. Mangione was never a UnitedHealthcare member, the company said.

The 2024 killing

Thompson, 50, was shot in the back on the morning of Dec. 4, 2024, as he walked toward a Midtown hotel for UnitedHealth Group's annual investor conference. He was a husband and a father of two. The killing set off a five-day manhunt that ended when a customer at the Altoona McDonald's recognized Mangione from photos released by the New York Police Department. Mangione is a University of Pennsylvania computer-science graduate from a prominent Baltimore real-estate family; handwritten notes recovered on his arrest railed against "parasitic" health insurers and called "Unabomber" Ted Kaczynski a "political revolutionary" who may have inspired him, according to a law-enforcement bulletin reported by the AP.

The double-jeopardy fight

Agnifilo told reporters outside court that her client has been "unfairly treated since the outset in every way" and faces "two simultaneous prosecutions in two jurisdictions who are trying to punish him twice for the exact conduct" — a claim her team put in writing Friday in a motion to dismiss the state murder charges under New York's double-jeopardy statute, which is broader than the Fifth Amendment clause and generally bars successive prosecutions for the same conduct. Manhattan District Attorney Alvin Bragg's office said it will fight the motion, arguing that federal stalking and state second-degree murder are legally distinct offenses with different elements. State Supreme Court Justice Gregory Carro will decide the question, and legal analysts told CBS News they expect the September trial date to slip while he rules. Mangione's case has drawn an online following that has raised more than $1.5 million for his legal defense — a phenomenon NYPD Commissioner Jessica Tisch confronted Friday. "Violence is not a cause, murder is not a message, and a killer is certainly not a hero," Tisch said.

Federal sentencing is set for Dec. 18. If Carro allows the Manhattan case to proceed, jury selection is scheduled to begin in three weeks; a second-degree murder conviction also carries a maximum of life in prison. Pennsylvania weapons charges tied to Mangione's Dec. 9, 2024, arrest remain pending.