Mangione’s federal criminal complaint, unsealed on Thursday, hit him with two stalking charges, murder with a firearm, and a firearms offense. It justified the federal prosecution due to his alleged use of a bus to go from Atlanta to New York, “travel in interstate commerce,” and the use of a phone and the internet in the killing.

He was taken to Manhattan by helicopter and met at the helipad by a massive retinue of heavily armed police led by New York City Mayor Eric Adams.

“This act of terrorism and the violence that stems from [Mangione’s case] is something that will not be tolerated in the city. We wanted to personally be here to show the symbolism of leading from the front,” Adams told reporters.

He then decried the support Mangione was receiving, calling it “vile” and sending “the wrong message.”

Mangione was charged with terrorism on Tuesday by Manhattan District Attorney Alvin Bragg.

The accused assassin’s public perp walk was unusual, legal experts noted, reflecting the extraordinary nature of the case.

CNN senior justice correspondent Evan Pérez said that officials usually “go to extraordinary lengths to avoid perp walks because they are considered prejudicial.”

CNN chief law enforcement and intelligence analyst John Miller speculated that the heavy escort was intended to assuage parts of the sympathetic public from trying to free him.

“The security around Mangione today is because of what they’ve been seeing in terms of the public support for him and their security worries about somebody not trying to attack him, but to try and free him from law enforcement,” he said.

According to the New York City Police Department and released surveillance footage, UnitedHealthcare CEO Brian Thompson was shot multiple times at 6:45 a.m. Dec. 4 outside the New York Hilton Midtown hotel, where he was headed to a UnitedHealthcare investor conference. His assassin, believed to be Mangione, quickly fled the scene and was last seen in Central Park. He was caught in surveillance footage fleeing on a bike.

Mangione was caught days after, with police saying he was identified at a McDonald’s in Pennsylvania.

The alleged assassin has received an unprecedented wave of support, particularly from young people. An Emerson College poll found that 41% of 18- to 29-year-old voters believed the killing was somewhat or completely acceptable, compared to 40% who believed it was somewhat or completely unacceptable.

A fundraiser for Mangione has raised nearly $140,000 for his legal fund as of Tuesday, with donors sending messages of support. One anonymous donor called him a “MAN OF THE PEOPLE,” calling the McDonald’s worker who allegedly tipped off police a “CLASS TRAITOR.” Another anonymous donor called him a “hero and revolutionary,” sending a $100 donation.