Officer Stephen Fox of the Altoona, Pa., Police Department testified that Luigi Mangione gave him an unsettling warning as Fox began to frisk him just before his arrest.
“Mangione told me he had a jar of peanut butter in his coat pocket,” Fox said on the stand in Manhattan Supreme Court on Tuesday, Dec. 9 — exactly one year after Mangione was taken into custody on suspicion of murdering UnitedHealthcare CEO Brian Thompson in New York.
“Then he told me he had a knife in his right pants pocket,” Fox added.
Fox searched Mangione at a McDonald’s on East Plank Road in Altoona after Mangione allegedly presented officers with a fake ID under the name Mark Rosario.
Unlike some of the other officers who testified during five days of lengthy evidence suppression hearings, Fox appeared highly familiar with the case. Mangione’s defense team is seeking to have key evidence thrown out before trial.
On the stand, Fox described the killing as a “violent act of cowardice” and said he believed it was a “clear targeted assassination of an individual in the hierarchy of healthcare.”
Fox was one of two officers who went through Mangione’s large black backpack at the McDonald’s, along with Officer Christy Wasser. According to police body camera footage played in court, they discovered a fully loaded magazine wrapped in a pair of wet underwear. In the video, Fox can be heard saying, “It’s f—ing him, 100%.”
Both Fox and Wasser testified that they were concerned the backpack might contain an explosive device and decided to search it at the restaurant instead of transporting it elsewhere.
“You don’t want to blow Blue up,” Fox said in the footage, referring to his K9 partner. “You can blow me up.”
That search has become a central issue in the suppression hearings. Mangione’s lawyers argue that the backpack was searched illegally, without a warrant. Prosecutors and Altoona police maintain it was a lawful search “incident” to Mangione’s arrest on suspected forgery charges, though one officer can be heard in the footage questioning whether a warrant was required.
Authorities say that once the backpack was taken back to the station, officers found a handgun, a silencer and a notebook allegedly containing a “manifesto” expressing a desire to “wack” a health insurance CEO.
The defense has also focused on a brief hand-off of the backpack between the McDonald’s and the police station that was not captured on body camera video.
Fox testified that the exchange between him and Wasser, when he was called back to the restaurant, lasted about 10–12 seconds. But on Monday, defense attorney Karen Friedman Agnifilo suggested that during that brief window the two might have secretly searched the backpack and discovered the gun — or even planted it.
Fox further testified that he helped transport Mangione to the Blair County Courthouse for arraignment, where they were greeted by a large gaggle of media amid intense public interest in the case. As they were leaving, Fox said, Mangione turned to him and asked, “All these people here for a mass murderer, why?”
Mangione then stumbled because his legs were shackled and Fox was walking too quickly, Fox testified. He said he apologized, and Mangione replied, “It’s okay, I’m going to have to get used to it.”
During cross-examination, Agnifilo suggested that Fox improperly delivered Mangione’s Miranda warnings, claiming he did so before Mangione was formally under arrest in hopes of prompting him to talk. Fox rejected that characterization.
Mangione has pleaded not guilty to murder charges in both state and federal court, as well as to forgery charges in Pennsylvania. He is being held pretrial at the Metropolitan Detention Center in Brooklyn and is expected to face trial in 2026.
Earlier testimony in the hearings has included other Altoona officers involved in Mangione’s arrest and questioning, along with two prison guards who said they spoke with him while he was in solitary confinement.
