NEW YORK, Dec 11, 2024 (BSS/AFP) - The man charged with brazenly gunning down a top health insurance CEO in New York carried a handwritten manifesto of grievances against the industry, police said Tuesday, giving a possible motive for the first time.

Luigi Mangione, 26, yelled and struggled with officers as he was led into court in Pennsylvania wearing an orange jumpsuit, for a hearing on extraditing him back to New York.

He is accused of murdering UnitedHealthcare chief executive Brian Thompson on a Manhattan street last week, triggering a nationwide manhunt that ended Monday when he was recognized at a McDonald's restaurant in Altoona, Pennsylvania.

Mangione fought his extradition to New York, a complaint which Blair County prosecutor Peter Weeks described as creating "more hoops... to jump through", and a judge denied him bail as the process continues.

The defense lawyers now have 14 days to submit motions against moving Mangione to New York, Weeks said.

Defense attorney Thomas Dickey maintained his client's innocence, saying he had seen "zero" evidence that Mangione was the shooter.

The suspect, who attended the elite University of Pennsylvania and reportedly comes from a wealthy family, could be heard shouting "unjust" and "an insult to the intelligence of the American people" as officers bundled him out of a car and into court.

The revelation of a manifesto carried by Mangione appears to back up the theory that he was angered by the complex. costly and at times dysfunctional US health care system.

"I had an opportunity to read the manifesto," the New York Police Department's Chief of Detectives Joseph Kenny said on the Good Morning America TV show.

"It's handwritten. He does make some indication that he's frustrated with the health care system in the United States."

Kenny said Mangione decried how the US health care system is among the most expensive in the world and yet the country has a lower life expectancy than other developed nations.

"He was writing a lot about his disdain for corporate American and in particular the health care industry," said Kenny.

The New York criminal complaint alleges Mangione was found with "written admissions about the crime" but contains no further detail.

Police have not confirmed reports the words "delay" and "deny" -- language used by insurers to reject claims -- were written on bullet casings found at the scene.

- Suspect was 'shaking' -

Investigators interrogated Mangione over last week's murder which triggered global headlines and sent shockwaves through the American business sector.

He appeared at a Pennsylvania court wearing a dark sweatshirt late Monday and was led inside by Altoona police, flanked by New York detectives.

Mangione was later charged in New York on suspicion of one count of murder, two counts of second-degree criminal possession of a weapon and other offenses.

He is next due to appear in court on December 23, and has yet to enter a plea.

The White House condemned the shooting.

"Obviously, this is horrific. Violence to combat any sort of corporate greed is unacceptable," Press Secretary Karine Jean-Pierre told a briefing when asked about the grievances aired by Mangione.

The suspect was apprehended by officers following a tip from staff at the McDonald's, where he was found wearing a mask and a beanie while using a laptop, and gave officers a fake ID, charging documents show.

They then searched him and found what police called a "ghost gun" capable of firing 9mm rounds and equipped with a suppressor that could have been made on a 3D printer.

When officers asked if he had been to New York recently, Mangione "became quiet and started to shake," according to the criminal complaint.

One of the fake IDs found was one used to check in to a Manhattan hostel ahead of the attack, police said.

Mangione appeared to have health issues, living with serious back pain and undergoing surgery for the condition last year, according to a New York Times report quoting friends.

A photo on what appeared to be one of his social media accounts featured an X-ray of a spine with a medical implant.