Luigi Mangione has pleaded not guilty to a federal murder charge in the killing of UnitedHealthcare CEO Brian Thompson, as prosecutors formally declared their intent to seek the death penalty against him.

Luigi Mangione pleaded not guilty in New York federal court to the murder of UnitedHealthcare CEO Brian Thompson. Mangione faces a possible death sentence in the case if he is convicted of murdering Thompson,

The suspect in the United Healthcare CEO Brian Thompson’s murder, Luigi Mangione, has entered the Not Guilty plea in the case.