New York, New York - More details have emerged about Luigi Mangione, the suspect in the high-profile killing of a health insurance CEO, amid a social media frenzy after the 26-year-old's arrest.

Mangione was thrust into the spotlight Monday after police revealed he is their person of interest in the shooting of UnitedHealthcare CEO Brian Thompson, in a case that laid bare deep frustration with America's broken healthcare system.

News of his capture in Pennsylvania – following a tip from a McDonald's worker –triggered an explosion of online activity, with Mangione quickly amassing new followers on social media.

While some lauded him as a hero and lamented his arrest, others analyzed his intellectual takes in search of ideological clues.

A photo on one of his social media accounts includes an X-ray of an apparently injured spine. No explicit political affiliation has emerged.

Meanwhile, memes and jokes proliferated, many riffing on his first name and comparing him to the Mario Bros. character Luigi, sometimes depicted in AI-altered images wielding a gun or holding a Big Mac.

"Godspeed. Please know that we all hear you," wrote one user on Facebook. "I want to donate to your defense fund," added another.

According to Mangione's LinkedIn profile, he is employed as a data engineer at TrueCar, a California-based online auto marketplace.

But a company spokesperson told AFP Mangione "has not been an employee of our company since 2023."

Although he had been living in Hawaii ahead of the killing, he originally hails from Towson, Maryland, and comes from a prominent and wealthy Italian-American family, according to the Baltimore Banner.

The family owns local businesses, including the Hayfields Country Club, its website says.

A standout student, Mangione graduated at the top of his high school class in 2016. In an interview with his local paper at the time, he praised his teachers for fostering a passion for learning beyond grades and encouraging intellectual curiosity.

A former student who knew Mangione at the Gilman School told AFP the suspect struck him as "a normal guy, nice kid."

"There was nothing about him that was off, at least from my perception," this person said, asking that their name not be used.

"Seemed to just be smiling, and kind of seemed like he was a smart kid. Ended up being valedictorian, which confirmed that," the former student said.

Mangione went on to attend the prestigious University of Pennsylvania, where he completed both a bachelor's and master's degree in computer science by 2020, according to a university spokesperson.

While at Penn, Mangione co-led a group of 60 undergraduates who collaborated on video game projects, as noted in a now-deleted university webpage, archived on the Wayback Machine.

On Instagram, where his following skyrocketed from hundreds to tens of thousands, Mangione shared snapshots of his travels in Mexico, Puerto Rico and Hawaii. He also posted shirtless photos flaunting a six-pack and appeared in celebratory posts with fellow members of the Phi Kappa Psi fraternity.

X user also scoured Mangione's posts on the platform for potential motives. His header photo – an X-ray of a spine with bolts – remains cryptic, with no public explanation.

Finding a coherent political ideology has also proved elusive, though he had written a review of Ted Kaczynski's manifesto on the online site Goodreads, calling it "prescient."

Kaczynski, known as the Unabomber, carried out a string of bombings in from 1978 to 1995, a campaign he said was aimed at halting the advance of modern society and technology.

Mangione called Kaczynski "rightfully imprisoned," but added that "'violence never solved anything' is a statement uttered by cowards and predators."

According to CNN, handwritten documents recovered when Mangione was arrested included the phrase "these parasites had it coming."

Mangione has also linked approvingly to posts criticizing secularism as a harmful consequence of Christianity's decline.

In April, he wrote, "Horror vacui (nature abhors a vacuum)." The following month, he posted an essay he wrote in high school titled How Christianity Prospered by Appealing to the Lower Classes of Ancient Rome.

In another post from April, he speculated that Japan's low birthrate stems from societal disconnection, adding that "fleshlights" and other vaginal-replica sex toys should be banned.