A 26-year-old man arrested in connection with the shooting death last week of UnitedHealthcare CEO Brian Thompson in New York City has connections to California, including a brief stint as teaching assistant at Stanford, officials said Monday.

Luigi Nicholas Mangione is a “strong person of interest” and was taken into custody after he was spotted by an employee at a McDonalds restaurant Monday morning in Altoona, Pennsylvania, NYC police said in a press conference.

He was carrying a ghost gun with a silencer, multiple fake IDs, and a manifesto criticizing health insurance companies, law enforcement officials said.

New York City police said Monday that Mangione was born and raised in Maryland, has ties to San Francisco, and his last known address was Honolulu, Hawaii. 

Mangione’s LinkedIn page doesn’t include any ties to San Francisco, but shows that he worked for the past four years as a data engineer for TrueCar in Santa Monica. 

He also spent summer 2019 as an “Artificial Intelligence Teaching Assistant” at Stanford University in Palo Alto, where he “designed lesson plans and taught artificial intelligence to gifted high school students,” according to his Linkedin page.

Stanford officials said Monday that “a person by the name of Luigi Mangione was employed as a head counselor under the Stanford Pre-Collegiate Studies program between May and September of 2019.”

The New York City Police Department has identified as a person of interest wanted for questioning regarding the Midtown Manhattan homicide of United HealthCare CEO Brian Thompson on Thursday, Dec. 5, 2025 in New York. (New York City Police Department via Bay City News)

Thompson was gunned down on Dec. 4 outside the New York Hilton Midtown in Manhattan.