• Luigi Mangione is in court contesting evidence in the murder trial of UnitedHealthcare CEO Brian Thompson.
• His legal team seeks to exclude a 3D-printed gun and notebook as evidence, alleging unconstitutional conduct by police.
• Prosecutors argue that the evidence is relevant and should remain admissible for trial.

Luigi Mangione, the 27-year-old accused of murdering UnitedHealthcare CEO Brian Thompson, appeared in court for a pretrial hearing that could shape the outcome of his case. The hearing focuses on whether key pieces of evidence, including a 3D-printed gun and journal writings, should be admissible in the upcoming trial. Mangione's defense argues that police conducted an illegal search of his backpack during his arrest in Pennsylvania, which led to the discovery of this evidence. They are also contesting statements he made to police before being informed of his rights, which they claim violated his constitutional protections, according to abcnews.

The legal arguments began as prosecutors presented evidence gathered during the arrest, including a 911 call from a McDonald's manager who expressed concern that Mangione resembled the suspect in Thompson's killing. This call, played in court for the first time, detailed how customers became unsettled by Mangione's presence at the restaurant, indicating a proactive response from law enforcement, as reported by indiatimes.

Witnesses from the arrest included a Jefferson County corrections officer, who testified that Mangione declared he owned a 3D-printed pistol without prompting. This assertion has raised concerns among defense attorneys regarding its validity and the circumstances under which it was made, casting doubt on the legality of the evidence collected. His defense team has maintained that many of these findings were the result of an unlawful search and should therefore not be considered admissible in court, according to latimes and bbc.

Mangione, who has pleaded not guilty to both state and federal charges, could face life in prison if convicted at the state trial, and federal prosecutors are seeking the death penalty for related charges. The legal proceedings have garnered significant attention, with many of Mangione's supporters appearing in the courtroom dressed as characters from the video game Super Mario, highlighting a phenomenon where some view him as a folk hero amid criticisms of the healthcare industry, as noted by scmp and aljazeera.

As the court audience watched footage of Thompson's killing and Mangione's arrest, tensions ran high. The prosecution emphasized the gravity of the evidence against Mangione, stating they would introduce DNA evidence and other crucial testimonies that could link him directly to the crime scene, underscoring the potential ramifications of the case, according to sfgate and lemonde.