Luigi Mangione, the online version of him, was an Ivy League tech enthusiast who flaunted his tanned, chiseled looks in beach photos and party pictures with blue-blazered frat buddies.
He was the valedictorian of a prestigious Baltimore prep school who earned bachelor's and master's degrees at the University of Pennsylvania and served as a head counselor at a pre-college program at Stanford University.
With his credentials and connections, he could have ended up one day as an entrepreneur or the chief executive of one of his family's thriving businesses. Instead, investigators suspect, he took a different path.
The police now believe that Mr. Mangione, 26, is the masked gunman who calmly took out a pistol equipped with a silencer on a Midtown Manhattan street last week and assassinated Brian Thompson, the chief executive of UnitedHealthcare. He was arrested in Altoona, Pa., on Monday after an employee at a McDonald's recognized him and called the police. Officers said they found him with fake identification, a weapon similar to the one seen in video of the killing, and a manifesto decrying the health care industry.
Mr. Mangione, who faces a variety of charges related to the gun and fake ID, has not been charged in connection with the killing. But the authorities have said that he is a "person of interest" in the killing, and in the hours since his apprehension his baffling journey from star student to murder suspect has begun to come into focus.
Mr. Mangione was in regular contact with friends and family until about six months ago when he suddenly and inexplicably stopped communicating with them. He had been suffering the effects of a painful back injury, friends said, but then went dark, prompting anxious inquiries from relatives to his friends: Had anyone heard from him?
In July, one man tagged a social media account that appeared to belong to Mr. Mangione and said that he hadn't heard from him in months. "You made commitments to me for my wedding and if you can't honor them I need to know so I can plan accordingly," the man wrote in a now-deleted post.
Those six months will most likely become a focus for investigators as they try to piece together what connection Mr. Mangione may have to the killing -- and what he was doing in the time that no one could find him.
Mr. Mangone left behind a long series of postings about self-improvement, healthy eating and technology -- and a review of the Unabomber's manifesto.
Bullet casings left at the scene, scrawled with words like "deny" and "delay," left the authorities and the public wondering if the shooting was payback for health care insurers rejecting claims.
In the wake of the attack, social media seethed with resentment against the insurance industry, and the unidentified suspect became, to some, a folk hero.
Mr. Mangione came from a privileged upbringing, part of an influential real estate family in the Baltimore area that traces its lineage to Sicily.
His grandfather, Nick Mangione Sr., and grandmother, Mary C. Mangione, purchased the Turf Valley country club in Ellicott City, Md., in the 1970s and developed the golf course community.
In the 1980s, the family purchased Hayfields Country Club in Hunt Valley, Md. It also founded the nursing home company Lorien Health Services, and Mr. Mangione's father, Louis Mangione, became an owner. The family also owned the radio station WCBM, which airs politically conservative programs and has other real estate holdings. A cousin, Nino Mangione, is an elected member of the Maryland House of Delegates.
The family's wealth and work with charity made it well known in Baltimore. Luigi Mangione was "just the last person you would suspect," said Thomas J. Maronick Jr., a lawyer and radio host who knows several members of the Mangione family.
"It is just such a well-respected family and such a prominent family within Baltimore County," he said.
Luigi Mangione attended high school at the prestigious Gilman School in Baltimore, where he wrestled and played other sports and was the valedictorian of his graduating class in 2016. In a graduation speech, he described his class as "coming up with new ideas and challenging the world around it."
He thanked parents in attendance for sending him and his classmates to the school, which he described as "far from a small financial investment." Tuition is currently $37,690 per year for high schoolers.
Aaron Cranston, who became friends with Mr. Mangione during their time at Gilman, said he recalled Mr. Mangione as being particularly smart -- perhaps the smartest at the elite private school. Even before college, Mr. Mangione had already made a mobile app where users could fly a paper airplane through obstacles.
Mr. Mangione was social, friendly and never particularly political, Mr. Cranston recalled. He was ambitious and carried his long interest in computer science toward college.
"He was a big believer in the power of technology to change the world," Mr. Cranston said.
Freddie Leatherbury, 26, an accountant who lives in Catonsville, Md., graduated from Gilman with Mr. Mangione in 2016. He recalled Mr. Mangione playing soccer for the high school team and running track or cross country.
"Those are both such disciplined sports. It says a lot about who he was as a student," Mr. Leatherbury said. "He was very smart, a pretty big math guy, really well read and quite well liked to be honest. I don't have any bad memories of him. He had a very healthy social circle."
Race Saunders, 27, now a software developer who lives in California, recalled being "study buddies" with Mr. Mangione in high school. He remembered Mr. Mangione as a hard worker.
"We were all definitely leaning toward computer science," Mr. Saunders said.
In college, Mr. Mangione excelled in that field. The commencement program for the University of Pennsylvania's class of 2020 lists Mr. Mangione as a member of the school's chapter of Eta Kappa Nu, an academic honor society for students in electrical and computer engineering that was founded in 1904. The society is selective, inviting only the top quarter of the junior class and top third of the senior class in those majors for membership, according to its website.
Mr. Mangione's interest in computer games started at a young age, when he began exploring the community online, according to a now-deleted interview published on the University of Pennsylvania's campus events blog in 2018. From there, the interview said, he wanted to start creating games himself and taught himself to code in high school.
"That's why I'm a computer science major now, that's how I got into it," Mr. Mangione said in the interview. "I just really wanted to make games."
After college, Mr. Mangione worked or had internships with several tech companies, according to his LinkedIn profile and a former employer.
Mr. Mangione's profile said that he had worked as a software engineer at TrueCar, an online marketplace based in Santa Monica, Calif. The company said in a statement that he had not been an employee since 2023.
In recent years, Mr. Mangione lived for six months in Honolulu in a "co-living" space called Surfbreak that caters to remote workers.
R.J. Martin, the founder of Surfbreak, said that Mr. Mangione was well liked and respected, according to a friend who was acting as a spokesman for Mr. Martin.
But a painful and debilitating back injury kept Mr. Mangione from surfing and impinged on his romantic life, the spokesman added, and after Mr. Mangione moved away and underwent surgery he stopped replying to his Surfbreak friends.
Mr. Mangione was cited for trespassing while he was living in Hawaii, according to court records, which said that he had failed to observe a sign at the Nu'uanu Pali Lookout on Oahu on Nov. 12, 2023. He was carrying an ID with a Towson, Md., address and was fined $100.
His internet trail hinted at pain both physical and mental.
In January, Mr. Mangione left a review of a book containing the rambling manifesto of Ted Kaczynski, the Unabomber, on GoodReads, a social media site for bookworms.
"It's easy to quickly and thoughtless write this off as the manifesto of a lunatic, in order to avoid facing some of the uncomfortable problems it identifies," Mr. Mangione wrote of the document. "But it's simply impossible to ignore how prescient many of his predictions about modern society turned out."
One of Mr. Mangione's favorite quotes, listed on GoodReads, was, "It is no measure of health to be well adjusted to a profoundly sick society," from Jiddu Krishnamurti, the religious philosopher and teacher.
The GoodReads page also included self-help books about health and the human body, including, "Crooked: Outwitting the Back Pain Industry and Getting on the Road to Recovery."
A social media account that appears to belong to Mr. Mangione contains an X-ray image of a spine reinforced with surgical implants. The X-ray shows a spinal fusion, a procedure that uses screws and rods to fuse two levels of the spine to ease what can be serious pain, according to Hasit Mehta, a professor at New York Medical College.
Brian Chirikjian, who said he was a friend of Mr. Mangione's, was one of a few friends who said they had not heard from him over the past six months.
Mr. Cranston, the school friend, said that he was forwarded a message this year from Mr. Mangione's family. The family reported that it had not heard from Mr. Mangione in several months after he underwent surgery, and relatives were hoping his friends might know where he was.
Few friends, if any, did until his arrest on Monday morning.
Mr. Saunders, the high school friend, was shocked by the news, but was skeptical that his classmate had suffered a psychological break.
"I would be surprised if it was some kind of mental breakdown," he said.
For now, Mr. Mangione remains uncharged in the shooting, and investigators will be looking for any clues that might link him to it. One thing they were examining was a handwritten manifesto that Mr. Mangione had in his possession when he was arrested, according to a senior law enforcement official.
"These parasites had it coming," it said at one point, as well as, "I do apologize for any strife and trauma, but it had to be done."
At Mr. Mangione's arraignment in Pennsylvania on Monday, a judge asked him whether he was in contact with his family.
"Until recently," he replied.
Reporting was contributed by Emma Goldberg, Maria Cramer, Jesus Jiménez, Nicholas Bogel-Burroughs, Campbell Robertson, Callie Holtermann, Chelsia Rose Marcius, William K. Rashbaum, JoAnna Daemmrich, Jack Truesdale, Ryan Mac, Andy Newman, Brian Conway, Jan Ransom, Jacey Fortin, Shayla Colon and Heather Knight. Research was contributed by Susan C. Beachy, Kirsten Noyes and Kitty Bennett.