New York prosecutors seek to sustain their case against Luigi Mangione, despite his federal plea

NEW YORK (AP) — New York prosecutors sought Friday to keep their murder case going against Luigi Mangione, arguing that his federal guilty plea shouldn't end a separate, state-court case over the killing of UnitedHealthcare CEO Brian Thompson .

The state and federal prosecutions center on “different harms, different evils, different purposes, different crimes,” Manhattan Assistant District Attorney Joel Seidemann and colleagues wrote in a court filing.

Mangione's defense lawyers are trying to get the state murder and weapons charges thrown out, citing double jeopardy . It's the legal precept that broadly prevents a person from being repeatedly prosecuted for the same crime, though the particulars can be complicated and disputed when different courts are involved.

In response to prosecutors’ filing Friday, Mangione's attorneys pointed to their own previous court papers arguing that the state and federal governments are “prosecuting the same man twice for the same event.”

A ruling is expected in late autumn.

At stake is whether Mangione will continue to face a trial in a New York state court in Manhattan and, potentially, how much prison time he will serve if he's convicted. He's already looking at the likelihood of a lengthy federal sentence. A state conviction, if there is one, could add more time.

The Manhattan prosecutors argue that double jeopardy doesn't apply to Mangione's situation. Though their case and the federal prosecution both concern Thompson's December 2024 killing, the Manhattan prosecutors contend that the specific charges involve different legal elements and criminal conduct.

Mangione pleaded guilty in August to federal stalking and cyberstalking charges, admitting in court that he traveled across state lines to New York to kill Thompson and then shot him from behind on a Manhattan street . The 28-year-old said he gunned for the CEO after experiencing years of severe back pain and “navigating the obstacles of the health insurance system.”

In the state case, meanwhile, Mangione pleaded not guilty in 2024 to murder, weapons and fake-ID charges. If he goes to trial, his admission in federal court might be used against him.

Thompson, 50, led one of the United States’ largest health insurers. His killing — with ammunition that authorities said was marked “delay,” “deny” and “depose” — alarmed the healthcare industry while baring the anger that many Americans feel about it. Some people cast Mangione as a valiant figure , even as others, including public officials, said the killing was anything but heroic.

Mangione, a scion of a prominent Maryland real estate family , has undergraduate and master's degrees in computer science. He worked for a car-buying website for a time. He never had UnitedHealthcare's insurance, police said.