Luigi Mangione appears in court for the murder of UnitedHealthcare CEO Brian Thompson

Luigi Mangione, the 26-year-old man suspected of shooting and killing UnitedHealthCare CEO Brian Thompson in front of a New York City hotel, appeared in court on Friday for the first time since being charged with state murder and terror in December.

Mangione entered with his wrists and ankles bound, dressed in a bulletproof vest over a green sweater, as did many of his supporters both inside and outside the courtroom.

Craig Rothfeld, Mangione's prison consultant, made a motion to remove the shackles, which Judge Gregory Carro declined.

The judge declined, saying officials would prefer Mangione remain shackled "for security reasons."

The 26-year-old has pleaded not guilty to state charges but has yet to enter a plea to federal murder charges in connection with Thompson's death as the executive went into the hotel hosting UnitedHealthcare's annual investor meeting in Midtown Manhattan on December 4.

Prosecutors began the hearing by detailing the material they had already submitted to Mangione's lawyers, which included body camera footage and medical examiner forensic reports.  Karen Friedman Agnifilo, Mangione's primary attorney, stated that her team still required further information from prosecutors.

Prosecutors examined the evidence they had given over to the defense, which included police body camera footage, police reports, surveillance videos, data from a mobile phone dropped at the crime scene, autopsy reports, medical examiners' forensic files, and forensic DNA test materials.  Prosecutors said further information needed to be provided over to Mangione's legal team.

Judge Carro ordered Mangione's next hearing on June 26 and directed his legal team to file papers over objections from his defense.

No members of Mangione's family were present for the hearing.

A Manhattan grand jury indicted Mangione on 11 counts, including one instance of first-degree murder and two counts of second-degree murder, as well as additional weapon and forgery charges.

According to the Manhattan District Attorney, if convicted, he may face life in jail without the chance of release.

In a statement posted this week on a website for his legal defense, Mangione thanked his admirers, writing: “I am overwhelmed by — and grateful for — everyone who has written me to share their stories and express their support.”

“Powerfully, this support has transcended political, racial, and even class divisions, as mail has flooded MDC from across the country, and around the globe.  While it is impossible for me to reply to most letters, please know that I read every one that I receive,” the statement continued.