Mangione in court as lawyers seek to rule out notebook, gun and other key evidence

Luigi Mangione, the man accused of fatally shooting United Healthcare CEO Brian Thompson in Manhattan a year ago this week, has appeared in court as his lawyers challenge the admissibility of key evidence in his case.

Mr Mangione, 27, has pleaded not guilty to both state and federal murder charges, which carry the possibility of the death penalty.

The pre-trial hearing could last several days, as defence attorneys are expected to call a host of witnesses, including from Pennsylvania, where he was arrested at a McDonald's.

In September a judge threw out state terrorism-related murder charges against Mr Mangione, arguing prosecutors had failed to establish evidence to justify them.

Mr Mangione's legal team is now hoping to convince a judge to exclude evidence including a gun and a notebook in which prosecutors say he set out a motive.

The defendant was arrested days after he allegedly shot father-of-two Brian Thompson as he was walking into an investors' conference on a busy Manhattan street on 4 December 2024.

A date for either of his trials has not yet been set.

Walking into court on Monday, Mr Mangione wore a grey suit and shirt, and court employees removed his hand restraints before he sat, as his lawyers requested.

This week's hearing focuses on whether prosecutors illegally obtained evidence from Mr Mangione when they arrested him in Altoona, Pennsylvania, and whether it should be excluded as a result.

Defence attorneys are seeking to suppress some of Mr Mangione's statements he made to police after being arrested - including allegedly giving them a false name.

They argue he did so before police read him his rights, including the right to remain silent.

His attorneys are also hoping to exclude from the trial a 9mm handgun that prosecutors say matches the one used in the killing, as well as writings found in Mr Mangione's backpack.

Prosecutors have alleged that Mr Mangione - the scion of a prominent Maryland family who graduated from an Ivy League university - had written in his notebook about "the deadly, greed fueled health insurance cartel".

But defence lawyers are arguing his backpack was searched without a warrant, and the items found in it should be excluded for that reason.

Eliminating those two critical pieces of evidence - that point to a murder weapon and motive - would be a big win for Mr Mangione's legal team.

But the chances of that happening are "virtually non existent", said Dmitriy Shakhnevich, a criminal defence attorney in New York.

He said that's because there are a number of exceptions to constitutional rules that law enforcement must obtain a warrant for personal searches, including some that may cover this case.

"In a case like this where there's a manhunt for a violent suspect who committed this alleged crime in plain view in New York City, nobody's getting a warrant," Mr Shakhnevich said.

"When they get him, they're going to search him."

Prosecutors say they have other key evidence against the defendant, including DNA or fingerprints on items discarded near the crime scene.

Mr Mangione's attorneys are probably aware of the long odds of getting evidence excluded, Mr Shakhnevich said.

He added that the main reason why defence lawyers hold these type of proceedings is to preview trial testimony from law enforcement.

So far, the court has heard from New York Police Department Deputy Commissioner of Public Information Sgt Chris McLaughlin, who was asked to review surveillance images from after the shooting.

Prosecutors in court also played CCTV showing the killing. A worker who handled security cameras at the McDonald's in Altoona testified as well.

Mr Shakhnevich said the legal team wants to have this type of information from witnesses so they can be aware of what people might say at trial, and to be on the lookout for any inconsistencies in their statements.

"The benefit of the hearing is that you get to have law enforcement officials testify, and you get to bind them to testimony for a trial later on," he said.

Mr Mangione's legal team has also been pushing to bar the federal government from seeking the death penalty.

They have said comments from high-ranking officials, including Attorney General Pam Bondi, accusing Mr Mangione of the murder have prejudiced his case, which they claim is motivated by politics.