Luigi Mangione pleads not guilty to murder and weapons charges in UnitedHealthcare CEO's death

Mangione's initial appearance in New York's state trial court was preempted by federal prosecutors bringing their own charges over the shooting. The federal charges could carry the possibility of the death penalty, while the maximum sentence for the state charges is life in prison without parole.

Prosecutors have said the two cases will proceed on parallel tracks, with the state charges expected to go to trial first.

One of Mangione's attorneys told a judge that government officials, including New York Mayor Eric Adams, have turned Mangione into a political pawn, robbing him of his rights as a defendant and tainting the jury pool.

"I am very concerned about my client's right to a fair trial," said Karen Friedman Agnifilo.

Adams and Police Commissioner Jessica Tisch stood among a throng of heavily armed officers last Thursday when Mangione was flown to a Manhattan heliport and escorted up a pier after being extradited from Pennsylvania.

Friedman Agnifilo said police turned Mangione's return to New York into a choreographed spectacle.

"He was on display for everyone to see in the biggest stage perp walk I've ever seen in my career. It was absolutely unnecessary," she said.

In a statement, Adams spokesperson Kayla Mamelak Altus said: "Critics can say all they want, but showing up to support our law enforcement and sending the message to New Yorkers that violence and vitriol have no place in our city is who Mayor Eric Adams is to his core."

"The cold-blooded assassination of Brian Thompson — a father of two — and the terror it infused on the streets of New York City for days has since been sickeningly glorified, shining a spotlight on the darkest corners of the internet," Mamelak Altus said.

Friedman Agnifilo also accused federal and state prosecutors of advancing conflicting legal theories, calling their approach confusing and highly unusual. "He is being treated like a human pingpong ball between warring jurisdictions here," she said Monday.

State trial court Judge Gregory Carro said he has little control over what happens outside the courtroom, but can guarantee Mangione will receive a fair trial.

Authorities say Mangione gunned down Thompson as he was walking to an investor conference in midtown Manhattan on the morning of Dec 4.

Mangione was arrested in a Pennsylvania McDonald's after a five-day search, carrying a gun that matched the one used in the shooting and a fake ID, police said. He also was carrying a notebook expressing hostility toward the health insurance industry and especially wealthy executives, according to federal prosecutors.

At a news conference last week, Manhattan District Attorney Alvin Bragg said the application of the terrorism law reflected the severity of a "frightening, well-planned, targeted murder that was intended to cause shock and attention and intimidation."

"In its most basic terms, this was a killing that was intended to evoke terror," he added.

Mangione is being held in a Brooklyn federal jail alongside several other high-profile defendants, including Sean "Diddy" Combs and Sam Bankman-Fried.

During his court appearance Monday, he smiled at times when talking with his attorneys and stretched his right hand after an officer removed his cuffs.

Outside the courthouse, a few dozen supporters chanted, "Free Luigi," over the blare of a trumpet.

Natalie Monarrez, a 55-year-old Staten Island resident, said she joined the demonstration because she lost both her mother and her life savings as a result of denied insurance claims.

"As extreme as it was, it jolted the conversation that we need to deal with this issue," she said of the shooting. "Enough is enough, people are fed up."

An Ivy-league graduate from a prominent Maryland family, Mangione appeared to have cut himself off from family and friends in recent months. He posted frequently in online forums about his struggles with back pain. He was never a UnitedHealthcare client, according to the insurer.

Thompson, a married father of two high-schoolers, had worked at the giant UnitedHealth Group for 20 years and became CEO of its insurance arm in 2021.

The killing has prompted some to voice their resentment at U.S. health insurers, with Mangione serving as a stand-in for frustrations over coverage denials and hefty medical bills. It also has sent shockwaves through the corporate world, rattling executives who say they have received a spike in threats.