Dec. 8, 2025, 4:07 PM ESTBy Adam Reiss, Chloe Atkins and Mirna AlsharifItems found in Luigi Mangione’s backpack when he was arrested in Pennsylvania last year include a handgun, a silencer, a magazine with bullets wrapped in underwear and a red notebook that an officer called a “manifesto.”The second week of a complex pretrial hearing kicked off Monday in Manhattan Criminal Court with a focus on the moments leading up to the 27-year-old’s arrest in the murder of United CEO Brian Thompson. Mangione entered the courtroom wearing a dark gray suit over a blue dress shirt, taking a second to scan the room before taking his seat. He chatted with his attorneys animatedly before court was called to order. Altoona Police Officer Christy Wasser testified Monday that she responded on Dec. 9 to a call about a suspicious person at a McDonald’s. Body camera video from the arrest was played in court and showed Wasser searching Mangione’s backpack.When another officer asked Mangione if there was anything in the bag that they needed to be aware of, he responded, “I wish to remain silent.” Wasser was concerned that there was a bomb in the backpack. Luigi Mangione appears Monday for a hearing in Manhattan Criminal Court in the killing of UnitedHealthcare CEO Brian Thompson.Stephen Yang / Pool via Getty ImagesThe video shows Wasser pulling out a cellphone, passport and a magazine with bullets, which was wrapped in wet underwear. An officer in the background of the video could be heard saying, “It’s f—ing him, 100%.”After the Altoona Police Department arrested Mangione, Wasser continued inspection of his backpack, video showed. Wasser found a loaded handgun, a silencer and a red notebook, which she called a “manifesto” in court Monday. Prosecutors showed several photos in court Monday of items retrieved from Mangione’s backpack, including the gun, magazine with bullets, notebook, silencer, cellphone and passport, along with a PNC debit card, a Whole Foods Visa card and a Maryland driver’s license. Blair County First Assistant District Attorney Nichole Smith testified Monday that she had received a call the day Mangione was arrested. Given that Mangione had provided a fake identification card, Smith said she suggested that tampering and forgery would be appropriate charges for him. At the time, she “knew very little” about the shooting, she said. Mangione was arrested and charged in Pennsylvania with forgery, carrying a firearm without a license, tampering with records or identification, possessing instruments of a crime and providing false identification to law enforcement authorities.Smith said that she approved a search warrant that day that was meant to authorize continued seizure of Mangione’s items, as well as transferring the evidence to the NYPD. She said that the seized items were inventoried based on the charges.Last week, Altoona Police Officer Joseph Detwiler told the court that Mangione seemed nervous when he confronted him at the McDonald’s. Detwiler said he asked Mangione whether he was visiting family and Mangione replied that he was “homeless.”Detwiler testified that he “knew it was him immediately,” after Mangione removed his blue medical mask. Last week’s proceedings also featured testimony from Tomas Rivers, a guard at a Pennsylvania state prison Mangione was taken to. Rivers said Mangione was on “constant watch” because the prison wanted to avoid an “Epstein-style situation,” a reference to Jeffrey Epstein, a convicted sex offender who died by suicide in federal custody in 2019.Mangione is accused of killing Thompson, 50, on Dec. 4, 2024, as he was heading to a UnitedHealthcare investor conference in Manhattan.He faces New York state charges including one count of second-degree murder, seven counts of various weapons charges and one count of second-degree criminal possession of a forged instrument. He was charged with two federal counts of stalking, one count of murder through the use of a firearm, and one count of a firearms offense.Mangione has pleaded not guilty to nine state counts and four federal charges filed separately. The federal charges come with the possibility of the death penalty. Adam ReissAdam Reiss is a reporter and producer for NBC and MSNBC.Chloe AtkinsChloe Atkins reports for the NBC News National Security and Law Unit, based in New York.Mirna AlsharifMirna Alsharif is a breaking news reporter for NBC News.