What’s Next for Luigi Mangione After His Guilty Plea?

Two powerful prosecutor offices in New York City — the U.S. attorney for the Southern District and the Manhattan district attorney — have been on a collision course over the case of Luigi Mangione.

And that jockeying came to a head on Friday, when Mr. Mangione pleaded guilty to federal charges of stalking resulting in death in the December 2024 killing of a health insurance executive in Midtown Manhattan. His sentencing is scheduled for Dec. 18.

Mr. Mangione, 28, faces both state and federal charges in the death of UnitedHealthcare’s chief executive, Brian Thompson, as he walked into a hotel for an investor conference on the morning of Dec. 4, 2024. Surveillance video showed a hooded figure emerge from between parked cars, point a gun toward Mr. Thompson and shoot him from behind.

While Mr. Thompson bled on the sidewalk, the gunman fled the scene. A national manhunt ensued.

On Friday, Mr. Mangione told the judge overseeing his federal case, Margaret Garnett, that it was him who researched about the investor conference that December, with a homemade gun affixed with a silencer and fatally shot Mr. Thompson.

Mr. Mangione’s plea in the federal case now turns attention to his state case, where he is charged with second-degree murder, which carries a sentence of 25 to life. He has pleaded not guilty.

But the plea in the federal case complicates the state case, which is scheduled to go to trial next month.

While murder cases are typically prosecuted in state courts, federal prosecutors have said that Mr. Mangione crossed state lines to stalk and ultimately kill Mr. Thompson, which gave the federal government jurisdiction to prosecute him.

The impact of the federal plea on the state prosecution remains unclear and Mr. Mangione’s sentence in federal court could also play a part.

Following Friday’s hearing, Mr. Mangione’s lawyer said they had filed a motion in state court to dismiss his case on double jeopardy grounds, which bars someone from being tried twice for the same offense, with exceptions.

The dual prosecutions presented Mr. Mangione with an “intractable constitutional dilemma where would have to choose between which case to defend,” they wrote.

The Manhattan district attorney’s office, led by Alvin L. Bragg, is signaled it would fight that outcome.

A spokesman with the office said that state prosecutors were “encouraged that Mr. Thompson’s family received a measure of accountability.”

“While federal sentencing is pending, we are prepared to litigate the defense motions,” the statement said. “The Manhattan D.A.’s Office remains committed to seeking justice for Mr. Thompson and his family.”

Dual prosecutions are allowed through an exception to the U.S. Constitution protections against double jeopardy, according to the Supreme Court, allows federal and state governments to prosecute for the same conduct because they are considered “separate sovereigns” that are independent of each other.

New York provides stronger protections. Under state law, double jeopardy comes into play when a prior prosecution for the same conduct ends in a conviction by guilty plea or a resolution at trial.

Mr. Mangione’s lawyers have contended from the beginning that his dual cases bring up issues of double jeopardy. If they now file a motion arguing that the federal plea addresses the same crime as the state case, a judge may hold hearings to decide whether a state trial would indeed constitute double jeopardy.

Legal experts said Mr. Bragg’s office may be able to rescue the state case — or portions of it — using an exception to New York’s law and using a rule called the Blockburger test. The office would need to show that their prosecution is meant to address a very different kind of harm from the federal case.

In their filing on Friday, Mr. Mangone’s team tried to counteract that arguments by saying that the cases addressed the same harm: “The unlawful taking of human life.”

They would initially argue before Justice Gregory Carro, who is overseeing the state case and has already voiced displeasure at the possibility that the federal prosecution could jeopardize a state trial.

After Mr. Mangione was arrested, the federal and state prosecutor’s offices in Manhattan seemed to have arrived at an agreement that the state case would go to trial first.

But after federal prosecutors pushed for their trial to begin this year before a trial date had been scheduled in state court, Justice Carro said that they appeared to have “reneged” on that agreement.

He added that the state “did most of the work in this case to go first.”