Months Before C.E.O.’s Killing, the Suspect Went Silent. Where Was He?
New details are emerging about Luigi Mangione’s growing impatience with “a capitalist society” and his search for refuge in the mountains of Japan.

Mike Baker reported from Seattle; Nicholas Bogel-Burroughs from Altoona, Pa.; Shawn Hubler from Honolulu; and Jacey Fortin from New York.

After a drizzly hike through one of Japan’s lush mountain ranges earlier this year, Luigi Mangione, a computer engineer in his mid-20s who had set off on a long solo trip to Asia, paused to record a voice message to a friend he had met while traveling abroad.

Making his way that day along a river gorge in the Nara region, Mr. Mangione had fled his day-to-day life in Hawaii to soak in hot springs, meditate, catch up on books and do some writing of his own.

“I want some time to Zen out,” Mr. Mangione said in the recorded message on April 27, his voice quiet and contemplative.

It would be one of his last communications before he abruptly cut ties with a wide range of friends and family, who eventually set out on a desperate hunt to track him down. Seven months later, Mr. Mangione emerged from his isolation as the suspect in the brazen assassination of Brian Thompson, the chief executive of UnitedHealthcare, on a sidewalk in Manhattan.

Police investigators have been scrambling to trace Mr. Mangione’s movements not only in the days before the Dec. 4 shooting, but also in the months that preceded it — a period that has been shrouded in mystery.

But in new records and messages reviewed by The New York Times, along with interviews with a wide range of people who knew Mr. Mangione, a more complete picture has emerged of a young man struggling with debilitating medical problems and increasingly disillusioned with the society he lived in.

Friends and family members have been left bewildered by the jarring transformation of a young man who had seemed destined for a life of achievement. He was the valedictorian at his elite prep school in Maryland and a computer science graduate of the University of Pennsylvania’s acclaimed engineering program, with wide-ranging social connections and significant ambition.

But in recent years, his writings and messages also traced a darker journey, as he transitioned from a teenager who celebrated how his fellow students had secured an extra recess to a young man who reported being in “unbearable pain.” He frequently expressed alarm over the world’s increasing reliance on smartphones and social media.

During his trip to Asia, he lashed out at the “modern Japanese urban environment,” claiming that sex toys, automated restaurants and a more general lack of “natural human interaction” were responsible for falling birthrates and a dearth of human connection.

More and more, he expressed frustration that society at large seemed incapable of addressing these longstanding problems, and he expressed interest in those who said that violence might be a necessary next step.

In his possession at the time of his arrest in Altoona, Pa., the police said, were writings that captured his recent reflections and condemned a multibillion-dollar health care industry that he said had put profits ahead of extending lives: “Frankly, these parasites simply had it coming.”

Mr. Mangione is now charged with second-degree murder in the death of Mr. Thompson, the health care executive. His defense lawyer, Thomas Dickey, said his client was legally presumed innocent and urged the public to keep an open mind about whether he committed the crime.

‘Life-Halting’ Medical Trouble

Mr. Mangione’s medical struggles seemed to escalate during his studies at the University of Pennsylvania, where he joined a fraternity that focused less on partying and more on academics, compared with other organizations on campus. Not that he wasn’t up for a party: One video from his campus years shows him gleefully bursting a beer can open with his head.

But underneath Mr. Mangione’s friendly, accomplished exterior, he was struggling to adapt to college. He wrote on social media that his fraternity’s “hell week,” despite being “very tame,” had disturbed his sleep cycle and drastically worsened symptoms of “brain fog” that he had been experiencing since high school. What in the past had been minor disorientation, he wrote, was now upending his life.

Once a straight-A student, Mr. Mangione wrote in a series of since-removed posts on Reddit that he suddenly saw his grades slipping. Lectures and books were perplexing, and he struggled to focus even on YouTube videos. He tried playing chess with a roommate, but he could not conjure basic strategies to win.

“It’s absolutely brutal to have such a life-halting issue, especially since the issue itself wears down the critical/logical thinking mind you’d usually use to tackle it,” he wrote. “The people around you probably won’t understand your symptoms — they certainly don’t for me.”

Among those who struggled to understand his ailments were his doctors; he suggested that tests that might explain his symptoms kept coming back negative.

Mr. Mangione did his own hunting for answers. He talked about getting Lyme disease at age 13 and seeking out new tests as an adult. Some studies have found that effects of the disease, including fatigue, brain fog, pain, sleep disruption and tingling or numbness in parts of the body, can linger long after treatment.

Mr. Mangione also consulted with others online about irritable bowel syndrome and visual snow, a neurological condition in which a person’s vision is obscured by flickering dots. While he appears to have sought doctors’ help for his brain fog symptoms, he did not mention being treated for any mental illness.

Quitting His Job

Despite his struggles, Mr. Mangione continued to show academic brilliance and an entrepreneurial spirit. In the summer of 2019, he was chosen to be the head counselor of a precollege program at Stanford University. When he returned to Pennsylvania for the school year, one fellow student recalled, he was ready to make some money. He bought dozens of boxes of Christmas lights and stacked them in a stairwell at his off-campus apartment, selling them to students to decorate their residences around campus.

As the pandemic arrived during his senior year in 2020, and students finished the semester off campus, Mr. Mangione completed both a bachelor’s degree and a master’s degree simultaneously. He soon secured a job at TrueCar, a California-based tech company that connects car buyers and sellers.

Able to work remotely, Mr. Mangione moved in early 2022 to Honolulu, settling into a co-living space on the 40th floor of a high-rise near Waikiki, Hawaii. He had a private room in a complex that included a stocked kitchen, a joint living area and a stash of surfboards available for anybody to use.

But soon after, his medical troubles worsened following a group surfing lesson, and he complained that he had strained his back. Mr. Mangione told friends that he had long struggled with a spinal problem.

“His spine was kind of misaligned,” said R.J. Martin, who had founded the co-living space and grew to be friends with Mr. Mangione. “He said his lower vertebrae were almost like a half-inch off, and I think it pinched a nerve. Sometimes he’d be doing well and other times not.” In July 2023, Mr. Mangione wrote in a Reddit post that he had also slipped on a piece of paper, which caused more problems.

It hurt to sit down, he reported, and his leg muscles were twitching. He felt tingling and numbness in his groin.

Mr. Martin said that Mr. Mangione told him that he had no relationships because “he knew that dating and being physically intimate with his back condition wasn’t possible.”

For months, the suffering continued as he consulted with doctors and tried a variety of noninvasive remedies. He quit his job in early 2023, telling a friend that while it paid well, it was “mind-numbingly boring.” He said he wanted to spend more time doing yoga and reading.

But it is not clear how he paid for health care after that. In May, he turned 26, meaning that he could have been kicked off his parents’ health insurance plan. The family has not discussed his insurance coverage, and has declined requests for interviews, but a representative for UnitedHealthcare said on Thursday that Mr. Mangione had never had health insurance through that company.

His mind seemed to be on more philosophical matters by then.

Mr. Mangione had always been a voracious reader, consuming everything from self-help books to George Orwell’s “1984,” at times scribbling extensive notes or typing up outlines that would summarize the author’s views and how they might apply to his own life.

“Reflect on how current work can positively impact society,” he wrote while reading “Grit: The Power of Passion and Perseverance,” a book about how to overcome setbacks by intentionally cultivating tenacity.

“When we decide what to pay attention to in the moment, we are making a broader decision about how we want to spend our lives,” he wrote while reading “How to Break Up with Your Phone.”

After reading “Bigger Leaner Stronger: The Simple Science of Building the Ultimate Male Body,” he jotted notes about how to lift weights without exacerbating problems with his back.

Among his friends in Hawaii, he helped start a book club that began meeting in 2023. Mr. Mangione pushed for readings by Tim Urban, a writer and illustrator whose blog Wait, But Why, a compendium of science writing and cultural musings, is popular with Gen Z techies. The group also read “The Ape That Understood The Universe,” a favorite of Mr. Mangione’s that explores evolutionary psychology.

One focus of his reading was his ongoing back troubles, including “Crooked: Outwitting the Back Pain Industry and Getting on the Road to Recovery.”

In the summer of 2023, he decided it was time to pursue surgery, traveling back to the East Coast for the procedure. On Aug. 10, Mr. Martin texted him to ask how it had gone, and Mr. Mangione texted back a laughing emoji and photos of his spinal X-rays.

He reported on Reddit that the procedure was a success and that he could walk and sit just fine within days. He began encouraging others to consider surgery and to push back against doctors who might be wary of surgical solutions. He suggested at one point that people should perhaps tell their doctor that their back troubles were preventing them from working.

“We live in a capitalist society,” he wrote. “I’ve found that the medical industry responds to these key words far more urgently than you describing unbearable pain and how it’s impacting your quality of life.”

‘Peaceful Protest Is Outright Ignored’

Among his friends in Hawaii, there was a growing strain among members of his book group, participants said. Some of them were perturbed by Mr. Mangione’s book selections, which they felt were overly geared toward men and masculine pursuits. Others drifted away after a discussion about whether to read the writings of Ted Kaczynski, the so-called Unabomber, who had carried out a series of bombings over a period of 17 years, beginning in 1978, with the goal of calling attention to the cost to humanity of a world built around technology.

Mr. Martin said he was the one who proposed reading Mr. Kaczynski’s 35,000-word manifesto, but Mr. Mangione was also clearly a fan, praising it later on his Goodreads page, and giving it a four-star review. He wrote that while Mr. Kaczynski had been rightfully imprisoned for the bombings, “it’s simply impossible to ignore how prescient many of his predictions about modern society turned out.”

As part of his review, Mr. Mangione quoted what he described as “interesting” remarks from someone who had written about how companies “have zero qualms about burning down the planet for a buck, so why should we have any qualms about burning them down to survive?”

The passage went on, “Peaceful protest is outright ignored, economic protest isn’t possible in the current system, so how long until we recognize that violence against those who lead us to such destruction is justified as self-defense?”

After his surgery, Mr. Mangione toured the islands of Hawaii, visited family back in Maryland and then, early this year, set off on the trip to Asia, which included stops in Thailand and Japan.

He wrote that he found Japan’s densely urban environment to be “an evolutionary mismatch for the human animal.” But he loved the mountains, saying that one of his goals in Asia was to “do some Buddha.”

He described his travels in Nara with enthusiasm. “There’s like these tiny little villages here, on the side of the cliffs — I’ll send a photo. It’s super lush, there’s this beautiful river that cuts through the gorge,” he said in the voice message he left in April. “I think I want to stay here for like a month, and just meditate and just hot spring, and do some writing.”

One of the people he spoke to during his travels was Gurwinder Bhogal, a writer who was living in England. The two had a video call for about two hours in early May. Mr. Bhogal recalled Mr. Mangione leaning to the left on some political issues and to the right on others, and that he was interested in effective altruism and wary of smartphone addiction.

“Overall, the impression I got of him, besides his curiosity and kindness, was a deep concern for the future of humanity, and a determination to improve himself and the world,” Mr. Bhogal said. Mr. Bhogal recalled Mr. Mangione discussing health care briefly — he complained that health care in the United States was too expensive, and said that he envied the nationalized health care system in the United Kingdom.

A couple weeks later, Mr. Mangione sent another message to the friend he had met while traveling. He was on Mount Omine in Japan, which he noted was known for its tests of courage and also for prohibiting women from climbing it.

“This mountain is peak misogyny,” he wrote to the friend. But, he added, “I needed to stop getting distracted by women lol.”

A few days later, on May 25, Mr. Mangione’s Reddit account shows one final post, in which he shared a video on a subreddit dedicated to Mr. Kaczynski. The footage, titled “Streaming Overdose 2024, China,” showed dozens of people lined up along sidewalks, livestreaming themselves.

Not long after that, friends started to lose touch with Mr. Mangione. One texted him in June — “Where in the world are you?” — but received no reply. By the end of the summer, family members were reaching out to Mr. Mangione’s past friends, hoping for their help in tracking him down, saying they had not heard from him in months.

His relatives have not discussed when they last heard from him, or why they waited until Nov. 18 to file a missing person’s report in California.

Just a few days later, the police say, Mr. Mangione got on a bus that had originated in Atlanta, on his way to New York City.

Reporting was contributed by Reed Abelson, Dani Blum, David W. Chen, Brian Conway, Mattathias Schwartz, Callie Holtermann, Mike Isaac, Jesus Jiménez, Heather Knight, Juliet Macur, Andy Newman, Amy Qin, Jan Ransom, Campbell Robertson, Ashley Southall, Aric Toler and Jack Truesdale. Research was contributed by Susan C. Beachy, Kitty Bennett and Kirsten Noyes.

Mike Baker is a national reporter for The Times, based in Seattle. More about Mike Baker

Nicholas Bogel-Burroughs reports on national stories across the United States with a focus on criminal justice. He is from upstate New York. More about Nicholas Bogel-Burroughs

Shawn Hubler is based in Sacramento and covers California news, policy trends and personalities. She has been a journalist for more than four decades. More about Shawn Hubler

Jacey Fortin covers a wide range of subjects for the National desk of The Times, including extreme weather, court cases and state politics all across the country. More about Jacey Fortin