Luigi Mangione, who is accused of shooting UnitedHealthcare CEO Brian Thompson dead in New York City, has entered a plea of not guilty as prosecutors say they are seeking the death penalty

Luigi Mangione, the Maryland man accused of hunting down and killing a UnitedHealthcare CEO over what prosecutors said was "hostility toward the health insurance industry," pleaded not guilty at his Manhattan federal court arraignment on Friday to what could be death penalty charges.

Luigi Mangione pleaded not guilty to federal murder charges that carry a possible death sentence in the shooting of a UnitedHealth Group Inc. executive. Mangione, 26, is charged with stalking and shooting Brian Thompson outside a hotel in Manhattan on Dec. 4. Wearing a tan prison outfit, he entered the plea at a hearing in Manhattan Friday.