A. Homicide is justifiable when committed by a public officer or public employee or those acting by their command and in their aid and assistance:
(1) in obedience to any judgment of a competent court;
(2) when necessarily committed in overcoming actual resistance to the execution of some legal process or to the discharge of any other legal duty;
(3) when necessarily committed in retaking felons who have been rescued or who have escaped or when necessarily committed in arresting felons fleeing from justice; or
(4) when necessarily committed in order to prevent the escape of a felon from any place of lawful custody or confinement.
B. For the purposes of this section, homicide is necessarily committed when a public officer or public employee has probable cause to believe he or another is threatened with serious harm or deadly force while performing those lawful duties described in this section. Whenever feasible, a public officer or employee should give warning prior to using deadly force.