A valedictorian of the prestigious Gilman School and scion of a prominent Baltimore-area family, Luigi Nicholas Mangione was charged late Monday in the killing of UnitedHealthcare CEO Brian Thompson.

Police arrested the 26-year-old from Towson Monday morning after receiving a tip that he had been recognized at a McDonald’s near Altoona, Pennsylvania. Mangione was carrying a 3D-printed pistol, a black silencer and fake New Jersey driver’s license, Altoona Police wrote in charging documents. They recognized him from the “wanted” photos, they wrote.

When asked if he had been to New York recently, Mangione “became quiet and started to shake,” police wrote in charging documents.

Late Monday, Manhattan prosecutors filed murder and other charges against Mangione, according to an online court docket. He remained jailed in Pennsylvania, where he was charged with possession of an unlicensed firearm, forgery and providing false identification to police.

Thompson, 50, was gunned down Wednesday in Manhattan and the brazen, sidewalk killing launched a five-day manhunt and captured attention across the country. The spotlight descended on the Baltimore suburbs Monday as word spread that he was a member of a large and well-known Italian American family. Cars and traffic cones blocked the entrance to the Hayfields Country Club, where his parents live, as reporters gathered there and on the Towson street where he grew up.

Police said Mangione was born and raised in Maryland, with ties to San Francisco. He lived in Honolulu, Hawaii, until recently. He worked in data engineering, according to his LinkedIn profile.

A friend and former roommate, speaking on CNN, said Mangione had needed surgery earlier this year, and that Mangione showed him “heinous” images of screws in his spine.

“When you’re in your early twenties and can’t do basic things, it can be really difficult,” R.J. Martin, the friend, said. Martin said Mangione had surgery earlier this year. Martin remembers Mangione as a thoughtful person

Mangione graduated cum laude from the Gilman School in 2016. The school’s headmaster issued a statement calling the matter “deeply distressing.”

“We recently became aware that the person arrested in connection with the killing of the United Healthcare CEO is a Gilman alumnus, Luigi Mangione, Class of 2016,” Henry P.A. Smyth said. “This is deeply distressing news on top of an already awful situation. Our hearts go out to everyone affected.”

In his valedictory speech at the North Baltimore school, Mangione praised the school for instilling in him the “incredible courage to explore the unknown and try new things,” according to an excerpt on the school website. That same year, in a Baltimore Fishbowl article spotlighting local valedictorians, Mangione outlined his ambition to study artificial intelligence.

Mangione entered the prestigious all-boys school in the sixth grade, and showed an interest in computer science, according to the school yearbook. He interned with AppRoar Studios, an online games company.

At the University of Pennsylvania, Mangione completed both a bachelor’s and master’s degree in computer science, with a focus on artificial intelligence. One summer, he taught AI at a Stanford University pre-college program in California. He also interned as a programmer for the Hunt Valley-based Firaxis Games from 2016 to 2017, according to his LinkedIn profile.

After graduation, Mangione joined TrueCar, an online car marketplace, as a data engineer, according to his LinkedIn profile.

Gilman classmate Freddie Leatherbury called the news of his arrest a “total shock.”

”He was a smart kid, he was a nice kid and he was relatively unassuming,” Leatherbury said. “He had a healthy social circle and was very well read. He had a lot going for him.”

Leatherbury and Mangione weren’t close friends in school, but he was still upset to hear the news.

“Because he was a nice kid who had everything going for him,” he said. ”I guess he just got caught up in some ideologies after school. Something has to go pretty wrong to lead to this.”

Social media posts depict a software engineer who traveled to Puerto Rico, San Diego and Honolulu, where he lived briefly. He posted about philosophy and popular science, quoting figures like lifestyle guru Tim Ferris and health podcaster Andrew Huberman.

His profile on the social media site X featured a photo of him backpacking next to a photo of an X-ray showing a spine with hardware associated with a lumbar fusion.

Law enforcement sources told the Associated Press that Mangione had writings with him when he was arrested that appeared to be critical of the health insurance industry.

The Mangione family’s interests in Baltimore reach from development to politics and civic life.

His late grandfather, Nicholas Mangione Sr., who died in 2008, was a self-made real estate developer who owned country clubs, nursing homes and a radio station. And his grandmother Mary, who died in 2023 from Parkinson’s disease, was described in an obituary as a hospital benefactor and a music patron.

They purchased Turf Valley Country Club in Ellicott City in 1978, establishing it as a golf course resort and residential community, and later Hayfields Country Club in Cockeysville in 1986.

Family businesses also include the Lorien Health Services nursing homes and radio station WCBM-AM. Mary Mangione was a supporter of the Catholic Archdiocese of Baltimore, Greater Baltimore Medical Center, the old Baltimore Opera Company and the Walters Art Museum, eventually becoming a Walters trustee.

Del. Nino Mangione, a Baltimore County Republican, is a cousin, his office confirmed.

The lawmaker issued a statement on social media Monday night on behalf of the family, noting that it could not comment on reports of Luigi Mangione’s arrest.

“We only know what we have read in the media. Our family is shocked and devastated by Luigi’s arrest. We offer our prayers to the family of Brian Thompson and we ask people to pray for all involved,” the family wrote. “We are devastated by this news.”

Thompson, 50, was killed Wednesday outside the New York Hilton in midtown Manhattan, where UnitedHealthcare’s parent company, UnitedHealth Group, was holding its annual investor conference, police said.

The shooter appeared to be “lying in wait for several minutes” before approaching the executive from behind and opening fire, NYPD Commissioner Jessica Tisch said. He used a 9 mm pistol that police said resembled the guns farmers use to put down animals without causing a loud noise.

In the days since the shooting, police turned to the public for help by releasing a collection of photos and video — including footage of the attack, as well as images of the suspect at a Starbucks beforehand.

Photos taken in the lobby of a hostel on Manhattan’s Upper West Side showed the suspect grinning after removing his mask, police said.

Ammunition found near Thompson’s body bore the words “delay,” “deny” and “depose,” mimicking a phrase used by insurance industry critics.

Retracing the gunman’s steps using surveillance video, investigators say the shooter fled into Central Park on a bicycle, emerged from park without his backpack and then ditched the bicycle.

On Friday, police found a backpack in New York’s Central Park that they say the killer discarded as he fled from the crime scene to an uptown bus station, where they believe he left the city on a bus.

The shooter then walked a couple of blocks and got into a taxi, arriving at the George Washington Bridge Bus Station, which is near the northern tip of Manhattan and offers commuter service to New Jersey and Greyhound routes to Philadelphia, Boston and Washington, D.C., NYPD Chief of Detectives Joseph Kenny said.

The Associated Press and Banner reporters Dylan Segelbaum, Danny Nguyen, Darreonna Davis and Cody Boteler contributed to this article.