Luigi Mangione, the man accused of gunning down a health insurance executive on a Manhattan sidewalk, is for now withdrawing plans to introduce evidence at trial that he was undergoing an extreme mental health crisis at the time of the alleged killing, according to a Friday court filing.Mangione, 28, is accused of fatally shooting UnitedHealthcare CEO Brian Thompson outside a hotel in Midtown in December 2024. The brazen killing was widely condemned by public officials but became emblematic of