Luigi Mangione will return to court for Day 9 of the crucial evidence hearing in his New York murder case on Thursday. 

It is expected to be the final day of testimony before a judge determines whether the prosecution's key evidence against Mangione will be allowed in the state trial over UnitedHealthcare CEO Brian Thompson's killing in 2024. 

The pretrial hearing is focused on whether police officers legally searched Mangione's backpack on the day of his arrest at a McDonald's in Altoona, Pennsylvania. The decision will determine if evidence found inside his backpack — a pistol, silencer and notebook — will be admitted during the state trial. 

Mangione's defense team claims none of the evidence should be allowed in the trial because officers did not have a warrant to search his backpack at the time. Throughout the hearing, officers and supervisors from the Altoona Police Department have testified the search was legal and routine according to their department's policy. 

On Tuesday, an officer testified about his role as an evidence custodian and walked through the department's process for documenting and processing evidence. An NYPD lieutenant also testified about traveling to Altoona and bringing evidence to a crime lab in Manhattan. 

Police body camera video of Mangione's arrest, audio of 911 calls and photos of evidence have also been released during the hearing. 

Mangione's attorneys also argued the release of a video showing Thompson's killing in its entirety influences public perception and the jury pool. The judge said issues related to that would be addressed during the vetting of potential jurors. 

Mangione, 27, also faces a federal trial that includes the possibility of the death penalty. He has pleaded not guilty in both cases.