to protect border agents, including “a show or use of force (including lethal force, where necessary), crowd control, temporary detention. and cursory search.”
This does not authorize the use of lethal force to kill someone climbing a fence or rushing traffic lane. It authorizes lethal force to protect boarder agents or I assume members of the military,. If they kill unarmed people or people who are attacking them with threat of life (that is with lethal force) they will be guilty of manslaughter or murder.