A man whom New York police are describing as a "strong person of interest" in last week's murder of UnitedHealthcare CEO Brian Thompson has been arrested in Pennsylvania and identified as 26-year-old Luigi Mangione.

Mangione was recognized while dining in a McDonald's in Altoona, Pennsylvania, and as the New York Times reports, so far, Mangione's only known connection to Pennsylvania is that he attended UPenn. An Instagram post (since removed) from the spring of 2019 showed him with the Phi Kappa Psi fraternity at Penn.

The caption reads: "'WARNING: EMITS SHOWERS OF SPARKS. DO NOT PUT IN MOUTH. LIGHT FUSE AND GET AWAY' - the live firework in my mouth."

Mangione appears to have grown up well off in Maryland, and attended an expensive private school there, Gilman High School, where he graduated as valedictorian of his class in 2016.

He graduated Penn in 2020 with an engineering degree, and he also reportedly received a Master of Science in Engineering in computer and information science.

He lived in Hawaii in recent years, and his last Instagram post was from August 2021, from the Big Island.

He also appears to have spent the summer of 2019 at Stanford, and posted a series of photos and videos from there, saying he was "getting paid in half of these photos." A LinkedIn account suggests he was a "head counselor" and artificial intelligence teaching assistant at the school for that summer.

The Chronicle notes that Mangione appears to have reviewed the Unabomber Ted Kaczynski's 1995 manifesto on GoodReads, in addition to reviewing Aldous Huxley's Brave New World.

An employee at the McDonald's in Altoona recognized Mangione around 9 am today from the widely circulated photos of his face taken at a hostel in New York City last week.

Two police officers, afteer being tipped off by the employee, approached Mangione, as the Times reports, who was sitting with a laptop and a surgical mask on his face. The officers reportedly asked him to pull down his mask, and when they asked if he had been in New York City recently, Mangione reportedly started "shaking."

After giving the officers a fake ID, and being called out on it, they asked why he lied about his identity, and according to police Mangione replied, "I clearly shouldn’t have."

In his backpack, officers allegedly found a ghost gun and silencer, both made with a 3D printer.

The shooter who killed Thompson last week used a silencer.

According to the Times, via the officers, Mangione was also carrying "a handwritten manifesto that criticized health care companies for putting profits above care."

Business Insider reports that, according Mangione's online activity, he may have suffered from chronic back pain, and at one point posted an x-ray image showing four pins in what appeared to be his spine. He also reviewed several books on GoodReads related to back pain.

The publication further reported that Mangione was one of 37 grandchildren of a prominent Baltimore real estate developer, the late Nick Mangione Sr., who died in 2008.

Mangione was brought into a courtroom in Blair County, Pennsylvania Monday at 6 pm local time to be arraigned on gun charges. He is being held without bond.

This is a developing story.