Luigi Mangione has pleaded not guilty to 11 charges, including murder and terrorism, related to the killing of Brian Thompson, the chief executive of UnitedHealthcare.

The incident occurred on 4 December as Thompson was heading to an investor conference in Manhattan.

Mangione, 26, faces serious consequences, with federal charges potentially leading to the death penalty and state charges resulting in life without parole.

A small group of supporters gathered outside the Manhattan courthouse, some expressing frustration with healthcare companies.

One placard at the protest referenced phrases linked to tactics insurers allegedly use to deny claims.

Folk hero

Despite the serious nature of the charges, some view Mangione as a folk hero due to prevailing frustrations over high healthcare costs in the US.

He was captured in Pennsylvania after a five-day search, found with a gun that matched the murder weapon and carrying a fake ID.

After his extradition to New York, prosecutors confirmed that both state and federal cases would proceed simultaneously.

State charges claim Mangione aimed to intimidate the population and influence policy, while federal charges involve stalking and murder.

The case has drawn public attention, reflecting broader concerns about healthcare practices and the power of insurers in the US.