Police have named the "strong person of interest" in the shooting of UnitedHealthcare chief executive Brian Thompson in New York City as 26-year-old Luigi Nicholas Mangione.
Mangione was ordered held without bail and did not enter a plea in his first court appearance on Tuesday in Hollidaysburg, Pennsylvania. He faces five charges, including one felony count of forgery and one felony count of carrying a firearm without a licence, according to the criminal complaint.
His next court appearance will be on 23 December in Pennsylvania pending an expected warrant from New York, CNN reported.
He had been in Pennsylvania for "several days" after the shooting in Manhattan, according to lieutenant colonel George Bivens of the Pennsylvania State Police, speaking during a news briefing.
Mangione was born and raised in the state of Maryland and had ties to San Francisco in California, according to New York Chief of Detectives Joseph Kenny. Mangione was arrested in Pennslyvania - the state between Maryland and New York - but his last previous address was in Honolulu, Hawaii.
He was arrested after he was recognised by an employee at a McDonald's restaurant in Altoona. He was "sitting there eating", Kenny added.
He credited the tip to the wide circulation of a photo the New York City Police Department released of Mangione without a mask on.
"Luckily, a citizen in Pennsylvania recognised our subject and called local law enforcement," Kenny said.
Mangione was carrying a so-called ghost gun, a largely untraceable firearm that can be assembled at home using kits, that was likely manufactured on a 3D printer, a suppressor, as well as "multiple fraudulent IDs", including a New Jersey ID that matched the identity the suspect used to check into a New York City hostel before the shooting.
Sometimes referred to as a "privately made firearm," ghost guns do not have serial numbers, making them more difficult to track and regulate. Purchasing kits to build ghost guns online does not require a background check, so buyers can also sidestep the typical requirements that might come with buying a firearm.
Mangione was also carrying a handwritten document - "a three-page manifesto" - which railed against the health care industry and suggested violence is the answer, according to CNN.
"We don't think there's any specific threats to other people mentioned in that document, but it does seem that he has some ill will towards corporate America," Kenny said.
An official told CNN the following two quotes: "These parasites had it coming" and "I do apologize for any strife and trauma, but it had to be done," were written in the manifesto, which is currently in the possession of the Altoona Police Department.
Mangione also wrote he acted alone and that he was self-funded.
Accused shooter had major back surgery
The idea that Luigi Mangione is the suspect in the in the killing of Thompson, is "unfathomable," his former roommate R J Martin told CNN's Erin Burnett on Monday night.
Martin said he was "beyond shocked" by the news.
Martin said the two - who lived together in a co-living and co-working community in Hawaii - were not just roommates, they were friends.
"He was a very thoughtful person. Communicated really well, was friendly, had good relationships with everyone. He was even, in some ways, a bit of a leader," Martin said.
"When I first interviewed him, before he moved in, I remember he said he had a back issue, and he was hoping to get stronger in Hawaii," Martin said.
Martin said Mangione took a basic surf lesson that ended up leaving him in bed for about a week and that "it was really traumatic and difficult".
Martin also said Mangione had surgery earlier this year that left him with screws in his body.
"He sent me the X-rays," Martin said. "It looked heinous, with just giant screws going into his spine. After that, he called me once, I didn't pick up."
The communication between the two kind of fizzled out after that.
Martin said Mangione "never once talked about guns, never once talked about violence".
"He was absolutely a not violent person, as far as I could tell," Martin said.
Family
Mangione's Facebook account, which has since been deactivated, showed his hometown as Towson, near Baltimore, in the state of Maryland.
According to CNN, Mangione is the grandson of Nicholas Mangione, a prominent Baltimore real estate developer, and his wife, Mary C. Mangione, a philanthropist who died last year. The Mangione family owns Lorien Health Systems, a nursing home chain in Maryland, and Luigi volunteered there in 2014, according to his LinkedIn page.
Mangione is registered to vote at his family's address in Cockeysville, Maryland, a Baltimore suburb, and is registered as unaffiliated with a political party, according to the state's voter registration lookup website. He is the cousin of Maryland State Delegate Nino Mangione, a Republican, the state lawmaker's office confirmed to local media.
Private security guards were blocking access to the family's house on a golf club on Monday afternoon local time, CNN reported.
Education
Mangione was a cum laude (with distinction) graduate from the University of Pennslyvania, completing both a master's and bachelor's of science in computer engineering within four years. His concentration, or major, was in artificial intelligence, and his minor was in mathematics.
The University of Pennslyvania - commonly known as UPenn or Penn - is a private Ivy League university in Philadelphia. It has an acceptance rate of 7 percent, and is ranked 11 in the QS World University Rankings 2025.
Mangione was also the valedictorian at Gilman School - an all-boys independent school in Baltimore, Maryland - in 2016.
Work
According to LinkedIn, Mangione has been working as a data engineer at the car-buying website TrueCar - in Santa Monica, California - since November 2020.
However, a company spokesperson told local media CBS News that Mangione had not worked there since 2023.
Social media
A person matching his name and photo had an account on Goodreads, a user-generated book review site, BBC reported. Magnione gave four stars to a text called Industrial Society and Its Future by Theodore Kaczynski - more popularly known as the Unabomber manifesto.
Starting in 1978, Kaczynski carried out a bombing campaign that killed three people and injured dozens of others, until he was arrested in 1996.
Mangione quoted lines from an unnamed source he found "interesting", which included: "When all other forms of communication fail, violence is necessary to survive. You may not like his methods, but to see things from his perspective, it's not terrorism, it's war and revolution".
"Violence never solved anything' is a statement uttered by cowards and predators."'
CNN reported that, in total, Mangione's GoodReads profile listed him as reading or wanting to read nearly 300 books, including a book about mental illness, a biography of the creator of the atomic bomb and Michael Pollan's popular book on the science of psychedelics.
Also on GoodReads, he reported reading or wanting to read a number of books about coping with chronic back pain. His account on X that appears to belong to him features a background profile photo of what looks like an X-ray image of a spine with hardware from a surgery.
Posts addressed to the X account suggest that some of Mangione's friends have been trying to get in touch with him since earlier this year.
In July, one user tweeted at Mangione, "I haven't heard from you in months," urging him to respond to his wedding invitation. Three months later, another user posted, "Hey, are you ok? Nobody has heard from you in months, and apparently your family is looking for you."
Coverage
In a statement, UnitedHealth Group said it had received many messages of support from "patients, consumers, health care professionals, associations, government officials and other caring people".
However, many people - including UnitedHealthcare customers and users of other insurance services - reacted differently, according to the BBC.
It said those reactions ranged from acerbic jokes (one common quip was "thoughts and prior authorisations", an insurance-themed play on the phrase "thoughts and prayers") to commentary on the number of insurance claims rejected by UnitedHealthcare and other firms.
At the extreme end, critics of the industry pointedly said they had no pity for Thompson. Some even celebrated his death.
Tens of thousands of social media users mocked the death of the health insurance chief executive. A post by UnitedHealthcare's parent company mourning Thompson's death received more than 82,000 reactions as of Friday; 76,000 of them were laughing emojis.
And, as NBC News reported, TikTok users who would normally leap at the chance to identify an alleged criminal had stood down during the manhunt.
"I have yet to see a single video that's pounding the drum of 'we have to find him,' and that is unique," said Michael McWhorter, better known as TizzyEnt on TikTok, where he posts true crime and viral news content for his 6.7 million followers. "And in other situations of some kind of blatant violence, I would absolutely be seeing that."
CNN reported some had portrayed the killer as a man enacting vigilante justice against a healthcare system they say values profits over patients' lives, which could hinder some people's motivation to report possible sightings of him.
The words "delay" and "depose" were written on a live round and a shell casing linked to the shooter, CNN said, words similar to a popular phrase about the insurance industry: "delay, deny, defend".
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