The man suspected of shooting UnitedHealthcare CEO Brian Thompson made a significant appearance in court on Monday, December 9 in Hollidaysburg, Pennsylvania. Luigi Mangione, charged with five counts including one felony count of forgery, one felony count of carrying a firearm without a license, one misdemeanor count of tampering with records or identification, one misdemeanor count of possessing instruments of a crime, and one misdemeanor count of false identification to law enforcement authorities, was ordered held without bail and did not enter a plea. He is scheduled to next appear in court on December 23 in Pennsylvania.

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Mangione, 26, whose last known address was in Honolulu, was identified as a person of interest in Thompson's shooting in midtown Manhattan last week. He was arrested on December 9 in a McDonald's in Altoona, Pennsylvania, on firearms charges after an employee recognized him from photos the NYPD had circulated nationwide. The employee promptly called local police.According to the criminal complaint, Mangione allegedly gave a responding officer a New Jersey driver's license with a false name. As the officer "checked the information through the dispatch center," another officer noticed Mangione's unusual behavior. Mangione allegedly "became quiet and started to shake." Officers couldn't find any information from the New Jersey license he provided. They informed him that he was under "official police investigation" and would be arrested if he lied about his identity. Mangione then allegedly revealed his true identity as Luigi Mangione with a birth date of May 6, 1998. When asked why he lied, he allegedly said, "I clearly shouldn't have."Responding officers questioned the suspect who was acting suspiciously and was carrying multiple fraudulent IDs as well as a U.S. passport. He was also carrying a firearm and suppressor, "consistent with the weapon used in the murder," and a manifesto against health care companies. Police believe Mangione used a so-called "ghost gun" that he may have made from a 3D printer. The criminal complaint alleges that both the pistol, described as having a "metal slide and a plastic handle with a metal threaded barrel," and silencer were 3D-printed. The pistol had "one loaded Glock magazine with six nine-millimeter full metal jacket rounds," and during a search of Mangione's backpack, police also allegedly found "one loose nine-millimeter hollow point round."An image of the suspect sought in the December 4 shooting of CEO Brian Thompson was also presented. Thompson, 50, a father of two from Minnesota, was fatally shot outside the New York Midtown Hilton hotel on December 4 in what police called a "brazen, targeted attack." The shooter fled the scene on an electric Citibike he rode into Central Park. When caught on videotape exiting Central Park, he was still riding the bike but no longer carrying the backpack. NYPD detectives scoured the park and found the backpack on Saturday, December 7, containing a Tommy Hilfiger jacket and Monopoly money.The manifesto, the handwritten document officers allegedly found on Mangione when he was apprehended, "speaks to both his motivation and mindset," as stated by Tisch. Tisch did not reveal the exact contents of the manifesto. Kenny hinted that it seems Mangione "has some ill will towards corporate America." A source told PEOPLE that it assailed the health care industry.Authorities also discovered engravings on bullet casings found at the scene with the words "deny," "defend," and "depose." This is similar to the phrase "delay, deny, defend" used to describe the industry's strategy of rejecting claims, which was also the title of a 2010 book by Rutgers University professor Jay Feinman.Mangione grew up in Towson, Maryland. PEOPLE confirms he was the high school valedictorian at the Gilman School, a prestigious boys prep school in Baltimore. PEOPLE also confirms he has both a bachelor's and master's degree from the University of Pennsylvania. In 2016, Mangione founded Penn's Game Research and Development Environment, a club also known as UPGRADE.This is a developing story and will continue to be updated.