Luigi Mangione appears in court as his lawyers try to exclude evidence

NEW YORK - Lawyers for Luigi Mangione, charged with assassinating the chief executive of a health insurer a year ago, began arguing in state court in New York on Monday that some evidence should be excluded from his trial.

Mangione, 27, was arrested on Dec. 9, 2024, five days after the executive, Brian Thompson of UnitedHealthcare, was shot while walking into a Hilton hotel on West 54th Street to prepare for an investor gathering.

For this week's hearings, which are expected to last several days, Mangione is appearing at the Manhattan criminal courthouse for the first time since the judge overseeing the state case, Gregory Carro, threw out terrorism charges against him in September. Mangione still faces an accusation of second-degree murder and other charges, and if convicted, he could receive a sentence of 25 years to life. He also faces federal charges.

Mangione's lawyers have argued that the police violated his constitutional rights during his arrest in Altoona, Pennsylvania, and so physical evidence taken from his backpack and the statements he made at the time should not be allowed.

Prosecutors have said that Mangione had writings denouncing America's system of for-profit health care and the "parasites" of the insurance industry. A journal detailing plans for the assassination was also found in Mangione's possession, according to prosecutors.

On Monday, Mangione appeared in the courtroom around 10:45 a.m., wearing a gray jacket and a red-and-white checkered shirt. After his handcuffs were taken off, he sat down next to his lawyers, and turned to scan the room behind him.

About two dozen supporters sat in the back rows, many wearing green in what has become their signature color. They craned their necks to get glimpses of Mangione, with giddy smiles, laughter and whispers.

Outside the courthouse, a van projecting Mangione's image and slogans of support on a screen circled the streets. Another van trailed behind, showing statistics about the health insurance industry. A small group of demonstrators had gathered, including a pink costumed frog hoisting a banner that read "Luigi before parasites."

Here's what to know about what's being argued this week:

A parade of witnesses

Prosecutors will most likely call a score of witnesses to testify and be cross-examined. The outcome could be consequential, according to Amber Baylor, founding director of the Criminal Defense Clinic at Columbia's law school.

"It can significantly impact whether or not a case is going to trial and then what will happen at trial," Baylor said.

Courts are hesitant to suppress key information, Baylor said, and exceptions often allow the use of evidence that was collected illegally.

Prosecution witnesses are likely to be mostly law enforcement agents, including the officers who arrested Mangione. Prosecutors could also show footage, including body-worn camera footage from the scene of his arrest, according to legal experts.

In a filing this year, prosecutors said 25 witnesses testified before the state's grand jury, six of them from Altoona and the remainder from New York law enforcement agencies.

The defense has asked to call two employees of the Altoona Police Department as witnesses.

What happened in Altoona

Thompson's killing quickly became one of the nation's biggest stories, and images of the man police said was the shooter were ubiquitous as the search went beyond New York City.

Around 9:30 a.m. Dec. 9, two Altoona police officers approached Mangione at a McDonald's, according to a defense motion. They asked Mangione to pull down his mask and asked for his name, telling him that someone had called police because "they thought he was suspicious."

Shortly after, one of the officers called a colleague to say he was "100% sure" that Mangione was the suspect, according to a defense filing.

Officers continued to speak with Mangione, patting him down and moving his backpack away from him, his lawyers wrote.

Later, after he was informed of his rights, he was searched again and handcuffed. An officer searched his backpack - without a warrant - and continued after Mangione was taken away, his lawyers said.

Officers found a handgun, a silencer, "a red notebook containing Mr. Mangione's personal writings, additional writings, a computer chip, an iPhone and several USB flash drives," his lawyers wrote.

Disputed evidence

Mangione's lawyers have asked that the judge suppress several of his statements, arguing that the officers in Pennsylvania violated his rights.

"The officers intentionally placed themselves in such a way to ensure Mr. Mangione could not leave," they wrote.

The lawyers have also asked that the evidence collected from his backpack not be allowed at trial because the officers took it without a warrant. They also asked that prosecution witnesses not mention the writings found in it.

Bennett L. Gershman, a Pace University law professor, said that people and their belongings are routinely searched during arrests to ensure the police's safety and to make sure evidence is not destroyed.

"There are a number of situations where the Supreme Court has said that you don't need a warrant," he said.

This article originally appeared in The New York Times.