Well, from a philosophical perspective: a sniper acting to save a life is acting in an emergency, whereas (presumably) an assassination ordered by the President (welcome to 2014, kid, please check your optimism and youthful enthusiasm at the desk) isn't.
"In an emergency situation, men’s primary goal is to combat the disaster, escape the danger and restore normal conditions (to reach dry land, to put out the fire, etc.)."
My take on that: under metaphysically normal circumstances, a court process is entirely appropriate. If you're in the position of the sniper, though (armed, and in a position to take a shot to save an innocent life) it's entirely rational to take the shot, and hope like hell that you were right.
"In an emergency situation, men’s primary goal is to combat the disaster, escape the danger and restore normal conditions (to reach dry land, to put out the fire, etc.)."
http://aynrandlexicon.com/lexicon/emergencies.html
My take on that: under metaphysically normal circumstances, a court process is entirely appropriate. If you're in the position of the sniper, though (armed, and in a position to take a shot to save an innocent life) it's entirely rational to take the shot, and hope like hell that you were right.