Timeline: Tracing the UnitedHealthcare CEO shooting suspect’s past

As New York authorities seek to extradite Luigi Mangione, 26, from Pennsylvania in connection with the Dec. 4 killing of UnitedHealthcare CEO Brian Thompson outside a Manhattan hotel, investigators are continuing to piece together the suspect’s history.

Mangione’s attorney, Thomas Dickey, has said he expects his client to plead not guilty to all charges filed against him.

Mangione, who is from a prominent Maryland family and attended the University of Pennysvlania, had posted about suffering back pain and was found with writings that suggested “ill will” toward corporate America, police have said.

Here’s what we know about some key moments in Mangione’s still-unfolding past.

More: Gun, fingerprints link accused shooter Luigi Mangione with CEO killing, police say

2016: A promising graduate

Mangione was raised near Baltimore. His late grandfather, Nicholas Mangione Sr., made a name for the family developing real estate, including a 1,000-acre golf club and resort hotel, according to his obituary on FamilySearch.org. He also owned two hotels, seven nursing homes, and two talk radio stations.

Among the suspect’s relatives is Nino Mangione, a cousin who is a member of the Maryland House of Delegates.

In 2016, Luigi Mantione graduated from the prestigious Gilman School, an independent all-boys K-12 school in North Baltimore, giving the valedictorian speech stressing courage and daring to be different.

More: 4 Stars for the Unabomber: ‘Person of interest’ in CEO slaying reviewed killer’s manifesto

2018: Recalling Lyme disease and other issues

In July of 2018, Mangione posted online about health issues, including having restless sleep.

The following month, he posted in an online group about irritable bowel syndrome. In other posts, he referenced battles with Lyme disease as a teenager and the “brain fog” that accompanied it. He missed soccer tryouts when he contracted Lyme at 13 and didn’t make the team, then started noticing “mild cognitive decline” when he was 15, he posted.

Mangione said his symptoms severely worsened in 2017, when he was a student at the University of Pennsylvania, but additional tests for Lyme disease were negative.

2019: A counselor in California

Mangione spent a summer at Stanford University working on a pre-collegiate program, according to his LinkedIn page, USA TODAY has reported. A Stanford spokesperson confirmed to the Los Angeles Times that he was a counselor in the program from May to September 2019.

2020: Graduating from the Ivy League

Mangione graduated cum laude from the University of Pennsylvania, studying engineering and applied sciences, according to his LinkedIn. His social media posts show him proudly surrounded by his Phi Kappa Psi fraternity brothers at school, as well as hanging out at Instagram-favorite sites in Mexico and Puerto Rico. During college, he founded a video game development club.

That same year, according to his LinkedIn profile, he started working as a data engineer at TrueCar Inc., an auto marketplace website based in Santa Monica, California.

2022: Hawaii, and talk of back surgery

Mangione spent the first six months of 2022 in Honolulu, Hawaii, at a cooperative living space called SurfBreak, according to an interview with its founder, R.J. Martin, in the Honolulu Civil Beat.  Mangione faced pain from his back issues, Martin said, and talked of an impending surgery.

Martin said Mangione cut off contact in the summer.

“He went radio silent in June or July,” Martin said.

2023: Pain and surgery

Mangione stopped working at TrueCar sometime in 2023, a company spokesperson told USA TODAY.

In July that year, a USA TODAY review of his Reddit posts shows, Mangione posted online that his “back and hips locked up after the accident and my whole lumbar / hips have been out of wack (sic) since then.”

Responding to another post that same month, he wrote about suffering bladder and genital pain, back pain and sciatica after the back injury. He experienced numbness in his groin and bladder, and below the right knee.

In August, he wrote an uplifting post on a sub-Reddit dedicated to spondylolisthesis, a condition that, according to the Mayo Clinic, occurs when spinal bones slip out of place and can cause chronic lower back and leg pain. The post was meant to encourage others suffering from back pain.

That same month, Martin told the New York Times, he checked in via text with Mangione after he’d left Hawaii earlier that summer, “and he sent me back pictures of his back surgery.”

2024: Missing, then infamous

In January, Mangione reviews The Unabomber Manifesto on Goodreads and gives it four out of five stars.

In May, Mangione reposted another social media user’s post related to health care, according to Business Insider. “My experience with the medical profession – and yours is probably similar – is that doctors are basically worthless unless you carefully manage them, and 2/3 of them are worthless even in that case,” the post said.

Some friends have told news outlets Mangione stopped communicating in the previous six months.

In July, according to the New York Times, one man tagged a social media account that appeared to belong to Mangione and said he hadn’t heard from him in months.  “You made commitments to me for my wedding and if you can’t honor them I need to know so I can plan accordingly,” the poster wrote in a post that has been deleted.

In November, Mangione’s mother reported him missing to San Francisco police two weeks before the shooting, John Chell, New York Police Department Chief of Patrol, told NewsNation.

On Nov. 24, police said Mangione arrived in New York City on a bus that originated in Atlanta, according to ABC, but it’s not clear where he got on. He later stayed at a New York hostel using a fake ID prior to the Dec. 4 shooting, according to police.

On Dec. 4, Thompson was shot at around 6:45 a.m. in Midtown Manhattan outside a hotel where he was set to speak at an investment conference. The alleged shooter left the scene on foot and took an electric bike into Central Park. The suspect was seen taking a cab at around 7 a.m. on the Upper West Side and at an uptown bus station about 45 minutes later, according to police.

On Dec. 5, police released images after working to analyze surveillance videos to track and identify the assailant in the manhunt that followed. The unknown killer becomes a twisted sensation on social media.

More: Video captures CEO shooting suspect Luigi Mangione yelling at media while entering court

On Dec. 9, Mangione was seen in Altoona, Pennsylvania by a McDonald’s employee who told police they saw him around 9:15 a.m. Mangione was “acting suspiciously” and carrying multiple fraudulent IDs, as well as a U.S. passport, according to the NYPD.

Mangione was charged in Pennsylvania with carrying a firearm without a license, tampering with records or identification, possessing instruments of crime and false identification to law enforcement. He was later charged with murder and four weapons felonies in New York City.

This article originally appeared on USA TODAY: Timeline: Where was Luigi Mangione before his arrest for CEO murder?