Luigi Mangione was back in court Tuesday for an eighth day of pre-trial hearings related to evidence in the killing of UnitedHealthcare CEO Brian Thompson a year ago in New York City. 

At issue is whether the police search of Mangione's backpack was legal, and whether the evidence contained in it can be admitted at trial. The search of the backpack turned up a pistol, silencer, and notebook.

The defense is arguing that all evidence found in Mangione's bag should be excluded from trial because there was no warrant.

"This is thick with legal issues"  

So far during the hearings, police officers and their supervisors from Altoona, Pennsylvania, have defended the search, testifying such searches are routine and in keeping with department policy once a person is placed under arrest. Mangione was arrested after giving officers who responded to a 911 call a fake ID. He was charged with forgery, a felony in Pennsylvania. 

"There is an active choice-of-law question here because obviously the arrest and the search was conducted in Pennsylvania, but all incident to a case in New York," said legal expert Rich Schoenstein, who was in court Tuesday morning. "They're raising genuine issues about this search of his backpack. I mean, what was it? Was it probable cause? Was it an incident to an arrest? Was it an inventory at the time he was taken into custody? It's not exactly clear what it was.

"This is thick with legal issues. These are serious constitutional questions about the defendant's rights, the defendant's right not to be subjected to unlawful search and seizure, the defendant's right to be read his Miranda rights, the right to remain silent. All of that is at issue here," Schoenstein added.

Another Altoona police officer took the stand Tuesday and testified that his role is evidence custodian. He walked the court through the department's process for documenting and processing evidence. Some of the evidence that was transferred to the NYPD, he testified, included CVS and Best Buy security footage, and a laptop Mangione allegedly used in a Best Buy.

After a break for lunch, an NYPD lieutenant testified about traveling to Altoona and taking all the property back with him to Manhattan, which was then brought to a crime lab.

Other evidence that has been released

During the evidence hearings so far, more photos of evidence and bodycam videos of the arrest at a McDonald's have been released by authorities. They have also released calls officers made to 911 in New York City to let them know they might have the UnitedHealthcare shooter in custody. 

Mangione's defense also is arguing that the release of the video that shows Thompson's killing in its entirety influences public perception. The judge said any issues related to that will be addressed during the vetting of potential jurors during jury selection.

The hearings will resume on Thursday.

So far, there's been no trial date set.

Mangione, 27, also faces a federal trial on charges that include the possibility of the death penalty.

Mangione has pleaded not guilty in both cases.