Luigi Mangione's defense is ramping up its fight against the death penalty early in a federal case in the alleged assassination of UnitedHealthcare CEO Brian Thompson.

Luigi Mangione was indicted Thursday on a federal murder charge in the killing of UnitedHealthcare CEO Brian Thompson, a necessary step for prosecutors to seek the death penalty.

Luigi Mangione, the man accused of gunning down UnitedHealthcare CEO Brian Thompson outside a Manhattan hotel in December, has been indicted in a New York court on four charges including a count eligible for the death penalty.