Federal prosecutors have revealed chilling new evidence that Luigi Mangione meticulously planned the murder of UnitedHealthcare CEO Brian Thompson for months before the fatal shooting outside the New York Hilton Midtown in December. Newly unsealed court documents detail diary entries and a letter allegedly written by Mangione, painting a portrait of premeditated violence fueled by animosity toward corporate greed.
One diary entry, dated August 15, shows Mangione reflecting on his delay in finalizing plans, which he described as a fortuitous opportunity to learn more about UnitedHealthcare, the company Thompson led. "The details are finally coming together," he allegedly wrote. Mangione referred to insurance as his "target" because it "checks every box," suggesting his disdain extended beyond a single company and toward the broader corporate landscape.
Prosecutors also cited a disturbing October 22 entry in which Mangione described the upcoming investor conference as a "true windfall" and emphasized that "the message becomes self-evident." In the same entry, he wrote about his intention to "wack" a CEO at the event, though he did not explicitly name Thompson. Six weeks later, Thompson was gunned down as he prepared to address the conference.
Further evidence includes a letter recovered during Mangione's arrest, addressed "To The Feds," in which he claimed to have acted alone and detailed his methodology. "I wasn't working with anyone. This was fairly trivial: Some elementary social engineering, basic CAD, a lot of patience," he allegedly wrote. The term "CAD" is believed to reference computer-aided design, a tool Mangione may have used to plan aspects of the attack. He added, "P.S. you can check serial numbers to verify this is all self-funded. My own ATM withdrawals."
Mangione, 26, was apprehended at a McDonald's in Altoona, Pennsylvania, days after the murder. On Thursday, he was extradited to New York, where he faced federal charges including murder through the use of a firearm, two counts of stalking, and a firearms offense. These charges are in addition to state-level charges filed by Manhattan District Attorney Alvin Bragg, including first-degree murder and terrorism-related counts. If convicted of the federal charges, Mangione could face the death penalty.
The federal complaint also sheds light on Mangione's alleged motivations, citing the diary and his letter as evidence of a deep-seated resentment toward corporate elites. Prosecutors believe his attack was intended to make a statement against perceived corporate greed, with UnitedHealthcare serving as his symbolic target.
Mangione's defense attorney, Karen Friedman Agnifilo, has dismissed the federal charges as excessive, calling them an unusual case of "piling on" and raising concerns about potential double jeopardy. Speaking outside the courthouse, Agnifilo declined to comment directly on the charges but pledged to mount a vigorous defense.
The federal indictment has drawn attention to Mangione's calculated planning and his broader grievances against corporate America. Investigators allege Mangione viewed the investor conference as the perfect stage for his violent statement, intended to reverberate beyond the event itself.
Mangione's arrival at Manhattan federal court on Thursday was marked by heightened security, with law enforcement officers carrying automatic rifles escorting him from a helicopter. He appeared in court wearing an orange jumpsuit, his wrists and ankles shackled.
Prosecutors believe Mangione's crime was intended to coerce and intimidate both civilians and corporate entities, a motive they say warrants severe punishment. Manhattan DA Alvin Bragg described the murder as a "frightening, well-planned, targeted attack" that disrupted one of New York City's busiest areas.
