The 26-year-old was allegedly detained with a gun, bullets, fake IDs, cash and a handwritten "manifesto".
www.bbc.com
The scion of a prominent Maryland family who was top of his class at an elite private school before graduating from an Ivy League university, Luigi Mangione seemed to have everything going for him, according to friends.
They were left stunned by the 26-year-old's arrest for the murder of UnitedHealthcare's chief executive Brian Thompson, who was fatally shot outside of a hotel in New York City on 4 December. Mr Mangione denies that he murdered the father of two.
According to a law enforcement, Mr Mangione was allegedly motivated by resentment at what he called "
parasitic" health insurance companies.
He had spent time in a surfing community in Hawaii, but left owing to debilitating back pain, say those who remember him. It is unclear, however, to what extent his own health troubles shaped his views of the medical industry.
Mr Mangione is currently being held without bail at a notorious jail in Brooklyn, also holding rapper Sean "Diddy" Combs. He is facing federal charges, as well as state charges in New York and Pennsylvania.
Federal prosecutors are pursuing the death penalty after charging him with multiple crimes, including murder and stalking.
US Attorney General Pam Bondi said the death penalty was necessary because he committed a "cold-blooded assassination that shocked America".
"After careful consideration, I have directed federal prosecutors to seek the death penalty in this case as we carry out President Trump's agenda to stop violent crime and Make America Safe Again," she continued.
Lawyers for Mr Mangione have called the move a "political stunt".
"Luigi is caught in a high stakes game of tug-of-war between state and federal prosecutors, except the trophy is a young man's life," said his lawyers, Karen Agnifilo and Avi Moskowitz.
In New York, Mr Mangione has been charged with 11 crimes, including murder and terrorism.
He also was charged in Pennsylvania with forgery, carrying firearms without a licence, tampering with records or identification, possessing instruments of crime and providing a false identification to police.
He was arrested five days after the attack, at a McDonald's in Altoona, Pennsylvania, and was allegedly in possession of a gun, bullets, multiple fake IDs and cash.
Mr Mangione also had a handwritten document that expressed "ill will" towards corporate America and included passages such as "frankly, these parasites had it coming", according to police.
Investigators say the words "deny", "defend" and "depose" were written on shell casings found at the scene of Mr Thompson's murder.
Law enforcement sources say this may be a reference to the "three Ds of insurance" - tactics used by companies to reject payment claims by patients.
Mr Mangione comes from a prominent family in the Baltimore area who are known for businesses including country clubs, nursing homes and a radio station according to local media.