Suspected UnitedHealthcare CEO assassin Luigi Mangione has pleaded not guilty to terrorism charges.
The 26-year-old shuffled into New York Supreme Court in chains on Monday morning, sporting a collared shirt, maroon sweater and orange shoes.
Mangione was shackled and seated when he leaned over to a microphone to enter his plea.
The Manhattan district attorney formally charged him last week with multiple counts of murder, including murder as an act of terrorism.
His initial appearance in New York state's trial court was preempted by federal prosecutors bringing their own charges over the shooting.
The federal charges could carry the possibility of the death penalty, while the maximum sentence for the state charges is life in prison without parole.
Prosecutors have said the two cases will proceed on parallel tracks, with the state charges expected to go to trial first.
Authorities say Mangione gunned down Brian Thompson as he was walking to an investor conference in midtown Manhattan on the morning of December 4.
Suspected UnitedHealthcare CEO assassin Luigi Mangione has pleaded not guilty to terrorism charges
The Manhattan district attorney formally charged him last week with multiple counts of murder, including murder as an act of terrorism
Thompson's slaying ignited scrutiny of the healthcare industry after bullet casings inscribed with the words, 'deny', 'defend' and 'depose'.
The messages bear similarity to a book by Jay M Feinman entitled, 'Delay, Defend, Deny: Why insurance company don't pay claims, and what you can do about it', which discusses the insurance industry's allegedly unethical practice of delaying and denying legitimate claims.
The discovery has led to Mangione being painted as a vigilante-style hero online by many people, while other deranged fans have simply been gushing over his good looks.
Mangione was arrested in a Pennsylvania McDonald´s after a five-day search, carrying a gun that matched the one used in the shooting and a fake ID, police said.
He also was carrying a notebook expressing hostility toward the health insurance industry and especially wealthy executives, according to federal prosecutors.
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