Luigi Mangione pleads guilty in federal case as state murder charges remain contested
Luigi Mangione has admitted guilt to federal charges while his defense team presses a New York judge to dismiss the state murder case against him. Former prosecutor Nancy Grace joined ‘Fox & Friends Weekend’ to examine the legal strategy surrounding the fatal shooting of UnitedHealthcare CEO Brian Thompson.
Luigi Mangione’s attorneys are intensifying their double jeopardy argument as they seek to prevent New York prosecutors from pursuing murder charges after their client pleaded guilty in federal court to what they describe as essentially the same criminal conduct.
The defense maintains that stalking someone with the intent to kill and then carrying out that killing amount to the same underlying harm.
The argument came in response to Manhattan prosecutors, who urged a New York judge to reject Mangione’s request to dismiss the state case. In federal court, Mangione admitted to killing UnitedHealthcare CEO Brian Thompson, a 50-year-old father of two who was shot in the back outside a Hilton hotel in Manhattan.

Luigi Mangione appears in Manhattan Supreme Court for a hearing in the murder case filed against him in connection with the killing of UHC CEO Brian Thompson on Sept. 16, 2025. (Curtis Means for DailyMail/Pool)
Prosecutors countered that double jeopardy does not apply because Mangione was not prosecuted on federal firearms charges. They said the New York murder case should continue because the state charges address a different “harm or evil” from the federal stalking offenses, even though Mangione acknowledged killing Thompson. They also argued that withdrawing a possible “extreme emotional disturbance” defense under New York law did not mean the federal proceedings prevented him from raising it.
Mangione’s attorneys, Karen Friedman Agnifilo, Marc Agnifilo and Jacob Kaplan, challenged each of those claims in a response made public over the weekend.
The defense first argued that Mangione was still “prosecuted” on the federal firearms allegations even though those counts were dismissed, meaning the double jeopardy protection remains relevant.
“The statutory definition of being ‘prosecuted’ for an offense does not require that the defendant plead guilty to that specific offense,” Mangione’s lawyers wrote.
Mangione pleaded guilty to two federal charges after initially facing additional allegations.
“In other words, when Mangione pleaded guilty to the federal indictment, the criminal action in which he had been charged with possession and use of the firearm was terminated for statutory double jeopardy purposes,” his attorneys wrote.

An NYPD Crime Scene Unit member photographs a shell casing at the location where UnitedHealthcare CEO Brian Thompson was shot and killed in Midtown Manhattan on Dec. 4, 2024. (REUTERS/Shannon Stapleton)
The attorneys also contended that stalking Thompson with the purpose of killing him constitutes the same “core misconduct” as the murder itself. They said New York’s double jeopardy law, which offers broader protection than the U.S. Constitution, requires prosecutors to establish that the state charges seek to prevent a different harm from the conduct covered by Mangione’s federal guilty plea.

UnitedHealthcare CEO Brian Thompson, left, is shown in a corporate headshot. He was killed Dec. 4, 2024, outside a Manhattan hotel while traveling to a shareholder conference. Luigi Mangione, the suspect, appears in court at right. (Businesswire, Steven Hirsch for New York Post via Pool)
“One of the harms clearly addressed by the expansive federal stalking statute is stalking with the intent to kill and resulting in the killing of the person stalked,” Mangione’s attorneys wrote. “It is a statute that, like a state murder statute, is intended to keep people safe from being murdered — the oldest crime there is.”
The defense acknowledged that the federal stalking charge includes additional requirements, such as interstate travel and electronic communications. But attorneys argued those factors are “not related” to the central harm at issue: the killing of another person.

Luigi Mangione appears in Manhattan Supreme Court for a hearing in the murder case filed against him in connection with the killing of UHC CEO Brian Thompson on Sept. 16, 2025. (Curtis Means for DailyMail/Pool)
“Travel and electronics are not the evils or harms being prevented,” the attorneys wrote. “The federal government does have an interest, however, in preventing people from [traveling] or using electronics as part of the crime of killing another person, or intending to do so. That is what makes the stalking statute similar to the murder statute in terms of the evils or harms both are looking to prevent.”
Mangione’s defense team is asking Judge Gregory Carro to throw out the state charges.
The Manhattan District Attorney’s Office, led by Alvin Bragg, did not immediately respond to a request for comment.