Luigi Mangione has pleaded not guilty in the December 4th shooting death of United Healthcare CEO Brian Thompson. Mangione voiced that not guilty plea to a judge Monday inside a New York City courtroom.

"The target is insurance because 'it checks every box,'" read a passage from a notebook, which was dated Aug. 15, that authorities found with Luigi Mangione, according to the court papers.

Luigi Mangione was charged in a four-count federal indictment that could land him the death penalty if convicted of murder.

Luigi Mangione, the suspected gunman in last week's killing of UnitedHealthcare CEO Brian Thompson, has been charged with murder. Reports described Mangione as the son of a prominent family in Baltimore who also surfed and worked in the tech industry.

A grinning Luigi Mangione appeared to yuk it up in a Manhattan courtroom Monday as he entered a plea in the murder of UnitedHealthcare CEO Brian Thompson.

Luigi Mangione was officially indicted on three counts of murder, as well as multiple weapons charges, in connection to the killing of Brian Thompson.

Luigi Mangione is now expected to face federal chargers in connection with the killing UnitedHealthcare CEO Brian Thompson in addition to state charges in New York and Pennsylvania, a Justice Department source confirms.

Luigi Mangione pleaded not guilty Monday to state charges in the murder of UnitedHealthcare CEO Brian Thompson.

Luigi Mangoine, who is accused of fatally shooting UnitedHealthcare CEO Brian Thompson, has pleaded not guilty. However, what online speculators noticed was the matching outfits of Mangione and his attorney as both of them appeared in court in clothes that seemed like a planned ‘twinning’.