Luigi Mangione, 26, was taken into custody by law enforcement in Altoona, Pa., the New York Police Department said Monday afternoon. Mangione was spotted by an employee at a local McDonald’s, who identified him eating at the restaurant.

Officials said Mangione was carrying a fake ID that matched the ID the suspect used to check into a New York hostel, which police were previously investigating in connection with the killing. Police said he also had a ghost gun, which may have been produced by a 3D printer, a silencer, and other forms of fake ID, as well as a face mask similar to the one worn by the shooter in surveillance videos.

Police in Pennsylvania also found a three-page, handwritten document on Mangione that gave them clues as to his mental state and motivations. When asked to elaborate on that document and whether the names of other corporate leaders were also mentioned, NYPD Chief of Detectives Joseph Kenny said: “We don’t think that there’s any specific threats to other people mentioned in that document, but it does seem that he has some ill will toward corporate America.” He added that the “investigation is leaning toward he was acting alone.”

The document was further described as a “manifesto” taking aim at the health care industry for prioritizing profits over patient care by two law enforcement officials, according to the New York Times.

According to the LinkedIn profile of a user with the same name, Mangione attended the University of Pennsylvania, an Ivy League school, where he earned both an undergraduate as well as a master’s degree in engineering as of 2020.

Although Margione’s LinkedIn profile lists his current workplace as TrueCar, an online car sales site, a spokesperson for the company fold Fortune he hasn’t worked there as an engineer since 2023.

On Wednesday, Dec. 4, Thompson, the 50-year-old CEO of UnitedHealthcare, was shot from behind on West 54th Street, as he approached an entrance to the Hilton hotel in Midtown Manhattan. He was presumably arriving early for his company’s investors’ conference, where he was scheduled to speak later that day.

Police previously revealed that three words were written on bullet casings found at the site of the shooting: “deny,” “defend,” and “depose.” The words seem to echo the title of a book about the insurance industry’s ethically suspect practices that allow companies to rake in billions by finding reasons not to cover medical treatments for paying customers: Delay, Deny, Defend.  

The writing on the ammunition casings fueled speculation about the shooter’s motives and was immediately incorporated into online memes about the shooting, often by people who were critical of the insurance company and the industry more generally.

A spokesperson for UnitedHealth Group, parent company of UnitedHealthcare, told Fortune: “Our hope is that today’s apprehension brings some relief to Brian’s family, friends, colleagues, and the many others affected by this unspeakable tragedy. We thank law enforcement, and we’ll continue to work with them on this investigation. We ask that everyone respect the family’s privacy as they mourn.”