Who is Luigi Mangione — the suspect in the killing of top US ...

The suspect in the high-profile killing of a top health insurance executive that has gripped the United States graduated from an Ivy League university, reportedly hails from a wealthy family, and wrote social media posts brimming with cerebral musings.

Luigi Mangione, 26, was thrust into the spotlight after police revealed he is their person of interest in the

. The father of two was shot dead in broad daylight in Manhattan in a case that laid bare deep frustration and anger with the US' privatised medical system.

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 spread, with many focusing on his first name and making comparisons 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," wrote another.

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

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

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.

"[He] 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.

While at university, 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 has skyrocketed from hundreds to tens of thousands, Mangione shared snapshots of his travels in Mexico, Puerto Rico and Hawaii. He also shared shirtless photos flaunting a six-pack and appeared in celebratory posts with fellow members of the Phi Kappa Psi, the American collegiate social fraternity.

However, it is on X (formerly Twitter) that users have sifted through Mangione's posts for possible motives. His header photo, an X-ray of a spine with bolts, remains enigmatic, with no public explanation.

Finding a clear political ideology has been difficult, though he did write a review of Ted Kaczynski's manifesto — popularly known as the Unabomber manifesto — on the user-generated book review site Goodreads, describing it as "prescient".

Mangione called Kaczynski "rightfully imprisoned" while also saying, "'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 criticising 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.

Thompson, 50, was gunned down outside a Manhattan hotel early on Wednesday morning by a masked man who appeared to have been waiting for his arrival before shooting the executive from behind.

The suspect ran from the scene and then rode a bike into Central Park. Surveillance video captured him exiting the park and taking a taxi to a bus station in northern Manhattan, where police believe he used a bus to flee the city.

The words "deny," "defend" and "depose" were carved into shell casings found at the scene, several news outlets have reported. The words evoke the title of a book critical of the insurance industry published in 2010 titled Delay, Deny, Defend: Why Insurance Companies Don't Pay Claims and What You Can Do About It.

Thompson's murder unleashed a wave of frustration from Americans who have seen their health insurance claims or care denied, faced unexpected costs, or paid more for premiums and medical care — all trends that are rising, according to recent data.

Thompson, a father of two, had been CEO of UnitedHealth Group's insurance unit since April 2021, part of a 20-year career with the company. He had been in New York to attend the company's annual investor conference.