'Hot assassin' Luigi Mangione ditches orange jumpsuit for courtroom chic ensemble as prison staff reveal how much fan mail he has received

Luigi Mangione ditched his orange jumpsuit for a more fashion-forward ensemble when he appeared in Manhattan federal court on Thursday.

The 26-year-old ladies' man was seen wearing his prison garb when he left a Pennsylvania court earlier in the day as he sported a clean-shaven look with a fresh haircut and an apparent eyebrow trim.

But when he appeared in a New York City courtroom to face murder charges for the December 4 shooting death of UnitedHealthcare CEO Brian Thompson, Mangione was seen wearing 'a white button-down shirt, navy three-quarter zip pullover and khaki pants,' TMZ reports.

He was not handcuffed during the hearing, but when the hearing ended, he was led from the courtroom by two US Marshals with his ankles shackled, according to CNN.

The accused murderer was indicted on charges of murder as an act of terrorism earlier this week, under a New York state law that allows for stiffer sentences when a killing is aimed at terrifying civilians or influencing government.

Yet many throughout the country have expressed their support for Mangione, who has received 54 emails, 87 pieces of mail and 163 deposits into his commissary account - which allows inmates to purchase items behind bars, since his arrest last week, the Independent reports.

His attorney representing him on Pennsylvania gun charges has also claimed that he declined offers from strangers to pay Mangione's legal bills, as his supporters raised over $100,000 for his defense fund.  

Any further fan mail will now be forwarded to the Metropolitan Detention Center in Brooklyn, where Mangione is being held in custody.

Prosecutors have argued in a newly-unsealed federal indictment that police found notes Mangione wrote, in which he expressed his desire to 'wack' the CEO off an insurance company.

He allegedly wrote about his disdain for the health insurance industry and its executives in a notebook police retrieved when he was arrested on December 9 in Altoona, Pennsylvania.

In one entry from August 15, Mangione allegedly wrote how 'the details are finally coming together' and that 'the target is insurance' because' it checks every box.' 

On October 22, Mangione allegedly wrote: '1.5 months. This investor conference is a true windfall... and - most importantly - the message becomes self evident.' 

UnitedHealthcare CEO Thompson was then gunned down on the street in the early morning hours of December 4 as he walked to a midtown Manhattan hotel where his Minnesota-based company was holding an investor conference. 

The shooting was captured on security video, but the suspect eluded police for days before Mangione was captured about 277 miles west of New York City.

There, police said they retrieved a manifesto outlining his grievances against UnitedHealthcare. 

'To save you a lengthy investigation, I state plainly that I wasn't working with anyone. This was fairly trivial: some elementary social engineering, basic CAD, [and] a lot of patience,' he allegedly wrote in the manifesto, according to the Daily Beast. 

He went on to say he had 'respect' for federal investigators, and apologized for causing any 'traumas,' but seemed to defend his alleged actions.

'Frankly these parasites had it coming,' the manifesto wrote. 

It claimed that the United States had the 'most expensive healthcare system in the world,' but blasted the system for making America only the 42nd in life expectancy.

Officers also said they matched a gun found on Mangione with the shell casings recovered at the scene and his fingerprints with a water bottle and energy bar wrapper found nearby.

Mangione was also said to be carrying a passport, a fake ID and about $10,000 in U.S. and foreign currency. 

He is now facing forgery, gun and tampering with records or identification charges - which his lawyer Tom Dickey has questioned.

He appeared in court on Thursday, when he waived a preliminary hearing on the Pennsylvania forgery and gun charges in exchange for the prosecutor giving him a 20-page investigative report from the Altoona Police Department. 

He then agreed to be extradited to New York, as officers waited to take the murder suspect back to the Big Apple.

Meanwhile, dozens of protesters showed up outside the Pennsylvania courthouse to support Mangione, holding signs with messages such as 'Health insurance practices terrorize people!' and 'Death by denial is murder!'

Some reportedly flew in from as far as California to support the alleged assassin, and at least two protesters were dressed as Luigi from the Super Mario Bros video game. 

Then, when Mangione arrived in New York, social media users noticed he kept pushing his tongue against his cheek.

While it's likely a nervous tic, the gesture sparked claims online that he was trying to send some sort of message to his supporters.

One X user wrote: 'Luigi, pushing his tongue against his cheek means “contempt”! Which Means DISRESPECT! He sent a signal to ALL!'

Another person on the discussion website called Datalounge agreed, claiming Mangione was 'showing his tongue up into his upper cheek. Wisdom tooth pain or secret terrorist signal?'

According to Vocabulary.com, the phrase 'tongue-in-cheek' describes an 'exaggerated facial feature meant to convey contempt or irony.'

In addition to the state charges in New York and Pennsylvania, Mangione is now facing federal charges of murder through use of a firearm, stalking and a firearms offense.

The murder by firearm charge could result in a death penalty.