Luigi Mangione, accused of fatally shooting an insurance executive in a case that has divided Americans, pleaded not guilty to murder charges after being arraigned in court Friday.
Mangione has now been charged in both New York state and federal court over the killing of UnitedHealthcare CEO Brian Thompson. He pleaded guilty to the federal charges in a Manhattan court on Friday.
The case has stirred debate about political violence and the state of the healthcare system in the United States, and is the first case in which the Justice Department is seeking the death penalty since Donald Trump returned to the White House.
Mangione wore beige prison scrubs and conferred with his lawyers, an AFP correspondent saw.
Outside the court, a van fitted with a video screen accused the Justice Department of "barbaric" conduct alongside an image of Mangione in court.
Well-wishers brandished signs and chanted, with one stopping to admonish prosecutors for rushing the cases against him.
Lindsay Floyd, an activist working in support of Mangione said ahead of the hearing that "these are serious accusations that deserve some reflection, not this vilification before the trial has even begun."
Early on December 4, Mangione allegedly tracked Thompson in New York, walked up behind him and fired several gunshots from a pistol with a silencer, federal prosecutors said. He had traveled to the city by bus from Atlanta about 10 days before the crime.
Mangione was arrested in Altoona, Pennsylvania, on December 9, following a tip from staff at a McDonald's restaurant after a days-long manhunt.
In the state case, Mangione has also pleaded not guilty and could face life imprisonment with no parole if convicted.
Elliott Gorn, a history professor at Loyola University Chicago, said that what struck him most in the days following the murder "was the deep sense of grievance that many Americans were suddenly talking about in the open."
"We'd just had a months-long political campaign, and the subject barely came up, but then suddenly the floodgates opened, and everyone seemed to have a horror story of medical care denied," he said.
