Put this code on a custom made actor, or even the brain (You just wont be able to do most missions that include a brain).
Code:
function Update(self)
for actor in MovableMan.Actors do
if actor.Team ~= self.Team then
actor:ClearAIWaypoints();
end
actor:GetController():SetState(Controller.WEAPON_FIRE,false);
end
end
end
This basically means: If any actors are not on the same team as this actor, then make it not move, and not fire.
They will still wave their gun around and such, and point it at you though.
Perfect for making a comic, eh?