It's been one year since Luigi Mangione was arrested in Pennsylvania in the killing of UnitedHealthcare CEO Brian Thompson. 

His pre-trial evidence suppression hearing continued Tuesday with a fifth day of testimony in New York City. 

Mangione's defense team is fighting to keep key evidence gathered during his arrest, including a pistol, notebook and more, out of his murder trial. 

Prosecutors argue the search of his backpack, conducted without a warrant, was proper and routine since it happened after Mangione was placed under arrest at a McDonald's in Altoona, Pennsylvania. Prosecutors say it is in line with standard arrest procedure. 

Mangione entered court just before 10 a.m. wearing a navy suit and pink button down shirt. 

"A violent act of cowardice"

Prosecutors started by calling Altoona Police Officer Stephen Fox to the stand. Fox testified he had heard about Thompson's killing on the news. 

"I knew it was a violent act of cowardice that targeted a defenseless human being," Fox said. 

Fox said when encountered Mangione in the McDonald's and they determined Mangione had provided them with the fake name Mark Rosario, he asked "Why are you lying about your name?" 

Fox said Mangione wasn't making eye contact with officers at the McDonald's, which made him feel uneasy. 

Fox told Mangione he was under official police investigation and read him his Miranda rights, and then Fox frisked him. Mangione told him he had a knife in his pocket. Fox told Mangione that anything he provides to police from that point forward that's false could result in his arrest on false identity charges. Fox told the court he detained Mangione on Pennsylvania charges, not New York ones. 

Fox took a photo of Mangione to share with the FBI for facial recognition purposes. 

"My suspicion was there was something in that bag that would harm human life," Fox told the court. 

"There's a weapon"

Monday, Altoona police officer Christy Wasser, who has been with the department for 19 years, testified. She is the officer who searched Mangione's bag. 

When officers asked Mangione if there was anything in the backpack they should know about, replied "I'm just gonna remain silent." Wasser said that immediately made her concerned that there could be a bomb in the bag.

Bodycam video played in court showed officers debating whether they needed a warrant before opening the bag. Inside, Wasser said she found wet underwear wrapped around a loaded magazine, knife and Mangione's passport. They also found a red notebook that appeared to outline escape plans. 

The bag was then taken to the police station for a more thorough search. 

Wasser could be heard on bodycam video saying "There's a weapon" as she pulled the pistol and what appeared to be a silencer from the bag. 

The defense argues all of that should be thrown out because there was no warrant at the time of the search. 

Mangione also faces federal charges, that are eligible for the death penalty. He has pleaded not guilty to all the charges.