The suspect accused of killing UnitedHealthCare CEO Brian Thompson has pleaded not guilty to murder and terrorism charges in New York state.
Luigi Mangione, 26, appeared in court on Monday to stand trial on 11 criminal charges, including murder as a terrorist offence.
He also faces federal charges of stalking and murder that could result in the death penalty.
Prosecutors allege that Mr. Mangione shot Mr. Thompson in midtown Manhattan before fleeing. Authorities later arrested him at a McDonald's restaurant in Pennsylvania.
Mr. Mangione faces 11 felony charges in New York State, including first-degree murder and murder as a terrorist offense.
If convicted of all charges, he faces a mandatory sentence of life in prison without the possibility of parole.
Mangione appeared in court Monday wearing a maroon blazer, white collared shirt and khaki pants.
In addition to the long crowd of journalists waiting for his court appearance, there were members of the public – almost all young women – in court, some of whom told CBS, the BBC's partner in the US, that they were there to show their support.
Federal prosecutors also separately charged Mr. Mangione with use of a firearm to commit murder and interstate pursuit resulting in death. Both charges could make him eligible for the death penalty.
He has not yet entered a plea to these charges.
Prosecutors said the federal and state cases will move parallel to each other.
