"Delay, Deny, Depose": Mangione's diaries reveal his chilling ideology

A Wednesday court filing by the Manhattan District Attorney’s Office has made public several handwritten pages found in Luigi Mangione’s possession, pages prosecutors now refer to as his "manifesto." The writings detail Mangione’s animosity toward the health insurance industry and his ideological motivations for the December 2024 shooting of UnitedHealthcare CEO Brian Thompson.

One August entry reads: "I finally feel confident about what I will do. The details are coming together. And I don’t feel any doubt about whether it’s right/justified." Other notes reference the Unabomber, Ted Kaczynski, not in admiration of his violent methods but in acknowledgement of how his message was misinterpreted due to indiscriminate brutality. "Normies categorise him as an insane serial killer, focus on the act/atrocities themselves, and dismiss his ideas," Mangione allegedly wrote.

Prosecutors argue that the attack—carried out as Thompson walked to an investor conference—was intended not as a personal vendetta, but as an act of ideological intimidation. "The particulars of the shooting itself - its target, its timing, its location, and the marking left on the ballistics - all made clear that defendant's intent was not to settle a personal vendetta or to steal something, but to violently broadcast a social and political message to the public at large," prosecutors wrote.

Shell casings left at the scene were inscribed with the words "delay," "deny," and "depose"—a direct critique of insurance industry practices. Prosecutors say Mangione's detailed planning and chosen target make the terrorism charge both justified and essential to the state’s case.

Mangione now faces 11 state charges in New York, including first-degree murder and terrorism. In Pennsylvania, he faces charges of criminal possession of weapons—including for a silencer—and possession of a forged instrument. Federally, prosecutors have charged him with stalking, murder through the use of a firearm, and firearm-related offences. They have announced plans to seek the death penalty. Despite this, Mangione has yet to enter a plea in any jurisdiction.

At the time of his arrest, authorities found three pages of handwritten notes totalling fewer than 300 words. According to law enforcement officials, the writings include chilling lines like "Frankly, these parasites had it coming," and a message to federal agents: "I do apologise for any strife or traumas, but it had to be done." Investigators say Mangione claimed he acted alone but have not ruled out the involvement of others.

Since the killing, Mangione has garnered a significant following among those disillusioned by America’s healthcare system. A legal defence fund has raised over $1 million. But the fallout has shaken corporate security protocols: UnitedHealthcare executives now travel with private security, avoid branded clothing, and have removed personal photos from public websites.

The FBI has recorded a spike in threats against healthcare professionals. Posters targeting executives, anonymous calls with death threats, and staff resignations have followed. Prosecutors note that Mangione’s writings aimed to instil fear and deter investment in the health insurance sector.

As Mangione awaits his June 26 state court appearance, his lawyers are fighting to reduce the visible markers of guilt—asking the judge to allow him to appear without shackles or a bulletproof vest. They argue that the excessive security measures prejudice jurors and violate his right to a fair trial.

Despite facing charges in multiple jurisdictions, Mangione has reportedly cooperated with authorities and behaved respectfully in court. Yet the new revelations from both his diary and arrest writings—detailing not only the planning but the philosophical underpinnings of the killing—could severely undermine the defence’s claim that he is being unfairly portrayed.

Whether the court sees him as a radical ideologue or a dangerous lone wolf, the Mangione case now sits at the explosive intersection of American anger, corporate power, and justice.

Source: CNN, CBS News