Luigi Mangione has pleaded not guilty to state murder and terror charges after allegedly shooting dead a health insurance CEO in New York.

Mr Mangione, appearing in Manhattan Criminal Court on Monday, faces life imprisonment without parole if convicted of killing Brian Thompson, the chief executive of United Healthcare, earlier in December 2024.

The 26-year-old entered the court under a heavy guard, wearing a red V-neck jumper over a white shirt for the brief hearing.

He pleaded not guilty to 11 state charges including first degree murder in furtherance of terrorism and two counts of second degree murder, one of which is charged as killing as an act of terrorism.

Federal prosecutors have brought a separate case against Mr Mangione which could see him face the death penalty if convicted of using a firearm to commit murder and interstate stalking resulting in death.