Suspect In Shooting Death Of UnitedHealthcare CEO Pleads Not Guilty To State Murder, Terrorism Charges

Luigi Mangione pleaded not guilty in a New York courtroom Monday to state charges in the murder of UnitedHealthcare CEO Brian Thompson earlier this month outside a Manhattan hotel. 

State prosecutors allege Mangione was found in possession of what is believed to be the murder weapon, and surveillance videos show a man matching his description before and after the attack, including outside the Hilton where Thompson was shot in the back.

Mangione entered court with his hands and feet shackled. He was wearing a maroon sweater over a white collared shirt and chinos. 

Among the long line of reporters who were waiting to get into the courtroom Monday morning, there were also members of the public - almost all of them young women - a few of whom told CBS News New York's Ali Bauman they were there to support Mangione. 

A key difference between the state and federal charges is that the state argues the shooting was an act of terrorism. Additionally, the federal charges open the possibility of the death penalty.

Mangione, 26, is being held at the Metropolitan Detention Center in Brooklyn after he appeared in federal court last week.

Luigi Mangione facing both state and federal charges

Mangione was flanked by heavily armed guards as he was extradited from Pennsylvania to New York last Thursday. He then appeared in federal court on stalking and murder charges.

In a statement, his attorney Karen Friedman Agnifilo called the federal charges "highly unusual," saying they raise "serious constitutional and statutory double jeopardy concerns."

The federal complaint revealed Mangione was found with a notebook containing handwritten pages that "express hostility towards the health insurance industry and wealthy executives in particular."

Manhattan District Attorney Alvin Bragg says his office is working with the federal government and, while the cases are happening simultaneously, the trials will have to happen at different times. Acting U.S. Attorney Edward Kim said he expects the state case to proceed first.