The federal charge that makes accused killer Luigi Mangione eligible for the death penalty must be dismissed because it does not meet the legal threshold, his defense attorneys argued in a new court filing.

Mangione has pleaded not guilty to federal charges that accuse him of shooting and killing United Healthcare CEO Brian Thompson in December of 2024.

Federal prosecutors allege Mangione stalked Thompson in Manhattan, where the executive was due to attend an investor conference at the New York Hilton Midtown. Mangione allegedly waited for Thompson to pass by and then shot him at close range.

“It is clear that, in its generic form, this crime can be committed without the use, attempted use, or threatened use of physical force against the person or property of another,” the defense said in the filing.

The defense also argued that evidence recovered from the backpack Mangione was carrying when he was arrested at a Pennsylvania McDonald’s should be suppressed. 

“Altoona law enforcement failed to follow fundamental Fourth Amendment case law (and basic police procedure) by failing to obtain a search warrant before searching through Mr. Mangione’s backpack and the closed containers within the backpack,” the defense said.

Prosecutors have previously defended the police handling of the arrest and search, which resulted in the recovery of the alleged murder weapon and writings that investigators said helped explain a motive.  

Mangione is accused of shooting and killing Thompson with a 9mm handgun equipped with a silencer on a Midtown Manhattan street on Dec. 4, 2024.

After a several-day manhunt, Mangione was captured in Altoona, Pennsylvania, where police found a backpack that investigators said contained the alleged murder weapon, a fake ID and a red notebook he used as a diary.

“I finally feel confident about what I will do,” one entry said, according to authorities. “The target is insurance. It checks every box.”

A federal grand jury charged Mangione in April with two counts of stalking, firearms offense and murder through the use of a firearm, a charge that makes him eligible for the death penalty, if convicted.

Mangione has pleaded not guilty to state charges in New York and Pennsylvania as well as the federal charges. The simultaneous prosecutions put him in what his attorneys have called an “untenable situation” and they’ve asked Judge Gregory Carro to dismiss the state case, or at least put it on hold.

Mangione is also being ordered to appear in a Pennsylvania courtroom regarding those state charges. While he is currently being held in the Metropolitan Detention Center in Brooklyn, the Blair County District Attorney’s Office in Pennsylvania wants the accused killer to appear in court for a pretrial motion hearing scheduled for Nov. 7.

In Pennsylvania, Mangione has pleaded not guilty to charges of forgery, possession of an instrument of a crime and giving a false ID to an officer.

In September, a New York judge dismissed two murder charges related to acts of terrorism, including the most severe charge, first-degree murder. The judge said the evidence presented to the grand jury was insufficient to support the terrorism charge.

Mangione is due back in federal court in December.