Luigi Mangione is accused of fatally shooting UnitedHealthcare CEO Brian Thompson outside a hotel in Midtown Manhattan in December 2024. He pleaded not guilty in both his state and federal cases. Judge Gregory Carro allowed prosecutors to use a seized gun and a notebook as evidence in Mangione's trial. However, according to Newsweek.com, Judge Carro ruled that five items seized from Mangione's backpack during his detention at a Pennsylvania McDonald’s could not be used at trial due to an improper warrantless search.

Luigi Mangione planned to argue that he was undergoing an extreme emotional disturbance at the time of the alleged killing, according to other and western sources. According to BBC, Mangione's defence team reversed their position on using the extreme emotional disturbance defence.

Mangione led law enforcement on a five-day manhunt after the killing, according to gdelt. He was held at the Metropolitan Detention Center (MDC) in Brooklyn, according to aetv.com. His federal trial was delayed from September to October 2026, according to aetv.com.