Luigi Mangione trial: Judge rules gun and laptop can be used as evidence in Brian Thompson murder case

A judge has ruled that a gun and laptop allegedly linking Luigi Mangione to the slaying of UnitedHealthcare CEO Brian Thompson can be used as evidence during his upcoming murder trial.

Judge Gregory Carro issued the ruling on Monday (May 18), rejecting defense arguments that the items were illegally seized before police obtained a search warrant.

The verdict is seen as a major victory for prosecutors ahead of Mangione’s murder trial, which is set to begin on September 8.

While the judge allowed prosecutors to use evidence obtained in a later inventory search at the police station, he ruled that some items found in an earlier warrantless search of McDonald’s must be excluded.

“I find that the search of the backpack at McDonald’s was an improper warrantless search,” Carro said in his decision.

Among the classified evidence were an ammunition magazine, a mobile phone, a passport, a wallet and a computer chip.

Prosecutors say the gun matches the murder weapon

According to prosecutors, the gun recovered from Mangione’s backpack was a 3D printed gun that matched the gun used in the killing of Brian Thompson.

Authorities say Thompson was fatally shot outside a hotel in New York City on December 4, 2024.

Mangione was arrested five days later at a McDonald’s restaurant in Altoona, about 230 miles west of Manhattan.

Prosecutors also pointed to handwritten notes found in Mangione’s backpack, including what they described as a “manifesto.”

The note allegedly referred to wanting to: “rip off” the head of a health insurance company

and included criticism of what prosecutors described as: “a deadly, greed-fueled health insurance cartel.”

The defense challenged the backpack search

Mangione’s attorneys argued that the evidence should be excluded because police searched the backpack before obtaining a warrant.

Police later obtained a formal arrest warrant, prosecutors said.

The legal battle focused heavily on body camera footage and testimony from Altoona police officers during a hearing in December.

The false name led to the arrest

According to testimony, Mangione initially gave officers a false name — “Mark Rosario” — when questioned by police.

Officer Stephen Fox testified that the false identity alone gave the officers grounds to arrest him.

“If he had given us his real name, he wouldn’t have committed the crime,” Fox said.

Police later discovered Mangione’s presented New Jersey driver’s license was fake after checking it against a law enforcement database.

An NYPD lieutenant testified that Rosario’s name matched the identity the suspect allegedly used to buy a bus ticket to New York and check into a Manhattan hostel.

Camera video played a key role

Judge Carro reviewed police body footage before handing down his sentence.

The video reportedly showed officers beginning to search Mangione’s backpack at McDonald’s before stopping after discovering a loaded gun magazine wrapped in his underwear.

Upon discovering the magazine, one officer says, “That’s him, dude. That’s him, 100%.”

Police later conducted what prosecutors described as an “inventory search” at the station, where officers found a firearm, a silencer, a laptop and other handwritten notes that allegedly contained possible escape plans.

Court dates set in state and federal cases

Mangione, 28, has pleaded not guilty in both his state and federal criminal cases.

His state murder trial is expected to begin Sept. 8 and could last four to six weeks.

Separately, jury selection in his federal stalking case is scheduled to begin Oct. 13, with opening statements expected Nov. 4.

If convicted on both counts, Mangione could face life in prison.