A man accused of killing a UnitedHealthcare executive appeared in Manhattan criminal court Tuesday as New York police warned that business leaders, political figures and other public-facing individuals may be at increased risk of targeted attacks.
Luigi Mangione is charged in state court with multiple counts, including murder as an act of terrorism, in the Dec. 4 slaying of Brian Thompson outside a midtown Manhattan hotel. Prosecutors say Mangione also faces federal charges, including stalking, and firearms and forgery counts in Pennsylvania where authorities arrested him. He has pleaded not guilty to state charges.
Authorities have said the shooting set off a massive manhunt. Investigators allege that shell casings recovered at the scene contained written messages and that cartridges taken from the alleged murder weapon were etched with memes and rhetoric tied to antagonistic political language. Prosecutors say Mangione stalked and ambushed Thompson, who was in New York for an investor conference; Thompson, 50, had spent two decades at UnitedHealth Group and became CEO of its UnitedHealthcare subsidiary in April 2021.
The NYPD's Counterterrorism and Intelligence Bureau, according to an internal threat assessment obtained by ABC News, warned that the risk of politically or ideologically motivated assassinations remains elevated. "These individuals likely remain vulnerable at open-air speaking engagements and public events, which have been targeted by malicious actors seeking to advance political or ideological agendas and/or draw attention to unique personal grievances through violence," the assessment said.
The warning followed a sniper killing last week of Turning Point USA founder Charlie Kirk during an outdoor event at Utah Valley University in Orem, Utah. Kirk had publicly warned in recent months about what he described as a rise in "assassination culture," and researchers and law enforcement officials have said the two incidents underscore heightened concerns about the vulnerability of speakers at open-air forums.
In Manhattan on Tuesday, visible security measures increased around some high-profile buildings. At the Blackstone building on Park Avenue, where a gunman stormed in this summer and killed four people, more than a dozen security guards were observed outside the main entrance. Court officers in earlier hearings also seized a handwritten note addressed to Mangione that had been smuggled into a proceeding, authorities said.
Mangione, described in court filings as an Ivy League-educated member of a wealthy Maryland family, has drawn an unusual level of online support despite the allegations. Supporters have gathered outside his court appearances dressed in costumes resembling the video-game character Luigi. Videos and social media posts showing supporters rallying outside the courthouse have circulated as the case has progressed.
Officials in New York and federal prosecutors continue to pursue parallel investigations. Federal authorities have charged Mangione with crimes related to stalking and violations of firearms law; Pennsylvania prosecutors have lodged additional charges for alleged forgeries and weapons offenses tied to the arrest there. Court records show he faces 11 counts related to the December shooting in New York, with some counts characterized by prosecutors as related to terrorism.
Thompson, a married father of two, had worked in the health-insurance industry for decades. Family members and company officials have publicly expressed grief and sought privacy since the slaying. UnitedHealth Group, the parent company of UnitedHealthcare, has not disclosed further personnel details beyond Thompson's professional biography.
Investigators have not publicly identified a clear motive tying the New York and Utah attacks. Law enforcement officials said they were monitoring possible copycat threats after the Utah sniper shooting and that the internal NYPD assessment was being circulated to private firms, political organizations and event planners to encourage heightened vigilance at public gatherings.
Prosecutors plan to move forward with both state and federal cases, and court proceedings are expected to continue as evidence is reviewed and pretrial matters are litigated. For now, New York police and federal authorities are urging organizers of public events to reassess security protocols and for potential targets to take precautions at open-air speaking engagements and other public appearances.
The case adds to mounting concerns among law enforcement, researchers and public figures about politically motivated violence and the security of public events. Authorities have said they will continue to investigate leads and to advise private and public institutions about threat mitigation as the legal process proceeds.