Luigi Mangione believed killing UnitedHealthcare CEO Brian Thompson to be a “symbolic takedown” and “a direct challenge” to the healthcare company’s corruption and “power games,” according to law enforcement sources who have reviewed the alleged murderer’s manifesto. Mangione, who had the three-page handwritten manifesto on him when he was busted at a Pennsylvania McDonald’s on Dec. 9, was likely driven to violence by his perceptions that the health care industry is “parasitic,” sources said.