Luigi Mangione's handwritten notebook has emerged as a key piece of evidence in the investigation of the murder of Brian Thompson, the CEO of UnitedHealthcare. Authorities have confirmed that Thompson's murder was not a hasty act, and the notebook contains detailed plans for the crime, including a chilling "to-do list."

In his notes, Mangione considered various methods to kill Thompson, including the use of a bomb in Manhattan. However, he ultimately decided against explosives, citing concerns that it would endanger innocent lives. Instead, he seemed to favor a more targeted approach, contemplating the idea of killing Thompson at an investors' conference where the CEO was scheduled to present company finances.

The notebook was found alongside a 262-page manifesto, a ghost gun, a silencer, and false identification during Mangione's arrest at a McDonald's in Altoona, Pennsylvania. The manifesto has been described by police as a "claim of responsibility" for the shooting, revealing Mangione's grievances against the healthcare system in the U.S. He criticized the high costs and poor life expectancy, expressing a strong disdain for corporate America and its practices.

Mangione had previously praised the writings of Ted Kaczynski, the Unabomber, and indicated that he wanted to challenge what he perceived as corporate corruption. His notes expressed a desire to confront these issues head-on, viewing Thompson's killing as a symbolic act against corporate greed.

In court, Mangione was denied bail and is facing extradition to New York to face murder charges related to the December 4 shooting, along with additional weapons charges in Pennsylvania.