A federal judge in New York said Monday she will hold a short hearing within two weeks to examine the police procedures that allowed officers to search Luigi Mangione’s backpack when he was arrested in connection with the December 2024 killing of UnitedHealthcare CEO Brian Thompson. U.S. District Judge Margaret Garnett said the hearing will call a single witness — an Altoona, Pennsylvania police officer — and will focus narrowly on what protocols were in place when Mangione was taken into custody.

The hearing could determine whether a gun police said matched the weapon used to kill Thompson and a notebook in which Mangione allegedly described his intent to kill a health insurance executive will be admissible as evidence in the federal death penalty case.

What the hearing will examine

Garnett said the Altoona officer selected as the hearing’s sole witness must have “sufficient authority and experience to testify about the established or standardized procedures in use” at the time of Mangione’s arrest “for securing, safeguarding, and, if applicable, inventorying the personal property of a person arrested in a public place.” The judge specified that the witness “need not have had any personal involvement” in the arrest itself.

She ordered prosecutors and defense attorneys to confer on a suitable hearing date, bringing Mangione back before the court sooner than a Jan. 30 conference already on the calendar.

Mangione has pleaded not guilty to federal and state murder charges. Both carry the possibility of life in prison; the federal case is a death penalty prosecution.

What was found in the backpack

Mangione was arrested Dec. 9, 2024, at a McDonald’s restaurant in Altoona, Pennsylvania — roughly 230 miles west of Manhattan — while eating breakfast. He was taken into custody five days after Thompson was shot dead as he walked to a Manhattan hotel for UnitedHealth Group’s annual investor conference. Surveillance video, according to the Associated Press, showed a masked gunman shooting Thompson from behind.

Officers began searching the backpack at the restaurant and found a loaded gun magazine, according to testimony at a recent court hearing. At a police station, an inventory search turned up a gun, a silencer, a notebook, and other documents that included what appeared to be to-do lists and possible getaway plans.

Mangione’s attorneys have asked Garnett to suppress all items from the backpack, arguing that officers began searching the bag without a warrant and that the search was therefore illegal.

Prosecutors counter that Altoona police policy requires officers to search an arrested suspect’s property promptly for dangerous items, and that a warrant was obtained afterward. The station-house inventory search — a procedure that catalogs every piece of a suspect’s seized property — is also required under department policy, prosecutors said.

As part of her inquiry, Garnett ordered federal prosecutors to provide her with a copy of the affidavit submitted to obtain the federal search warrant. Defense attorneys contend the pre-warrant search may have shaped how that affidavit was written. Prosecutors have said no specific details about the notebook’s contents were included in the document.

Laws governing warrantless searches and inventory procedures are frequently litigated in criminal cases and often turn on the specific policies and practices of the law enforcement agency involved.