Attorneys for Luigi Mangione are accusing the federal government of providing “barebones, vague allegations” in their death penalty case against the accused UnitedHealthcare CEO killer. 

In a new court filing, the defense is asking a federal judge to require the prosecution to hand over information surrounding allegations intended to be proven at the sentencing phase of Mangione’s death penalty trial. 

The defense claims prosecutors’ information about various factors – such as the alleged threat to individuals other than the victim and the impact on the victim’s loved ones – “contain only barebones, vague allegations, lacking any information about the facts upon which the government intends to rely,” according to the document. 

LUIGI MANGIONE’S TEAM ASKS COURT TO REMOVE ‘SHACKLES,’ BULLETPROOF VEST ON UNITEDHEALTHCARE CEO MURDER SUSPECT

Mangione’s legal team is arguing that the lack of details prevents them from preparing to defend their client against the allegations during the trial’s sentencing phase and is in violation of the Federal Death Penalty Act. 

The document suggests an “informational outline” should be provided to the defense by Oct. 24 – 90 days from its filing. 

“The need for sufficient time to conduct such an investigation is particularly acute in this case, because the government announced its intention to seek the death penalty even before the defense had an opportunity to conduct a mitigation investigation and make a detailed factual mitigation presentation to the Department of Justice,” the document reads. 

“[T]oo much is left to guesswork,” Mangione’s team wrote. “Notice means notice. It does not mean a scavenger hunt for clues in discovery.”

LUIGI MANGIONE ARGUES DOUBLE JEOPARDY IN BID TO DROP MURDER CASE, SUPPRESS EVIDENCE

Mangione is accused of gunning down UnitedHealthcare CEO Brian Thompson outside the Hilton Hotel in Midtown Manhattan on Dec. 4, 2024 before fleeing to Pennsylvania. 

Federal prosecutors allege Mangione used a homemade ghost gun to shoot Thompson twice in the back, with authorities believing the killing was ideologically motivated due to the words “deny,” “delay” and “depose” written on the ammunition found at the crime scene. 

Read the court filing here:

The Manhattan District Attorney’s office previously referred to the shooting as an act intended to “violently broadcast a social and political message to the public at large.” 

LUIGI MANGIONE PROSECUTORS FIRE BACK ON ‘EAVESDROPPING’ CLAIM

The prosecution also points to journal entries and a note addressed to the FBI by Mangione, in which he allegedly rails against the U.S. healthcare system, adding that “these parasites simply had it coming.” 

Mangione faces several federal charges, including alleged murder through use of a firearm and stalking. Additionally, he is facing state charges in a case that is expected to proceed ahead of his federal trial. 

Mangione has pleaded not guilty to all charges. 

The Department of Justice and Mangione’s legal team did not immediately respond to Fox News Digital’s request for comment.