You read my mind Barney- I thought the same thing when I read it.
Also, why are you walking down a deserted street with a .357 in your hand with your wife and small children?
Another option to avoid a lengthy stay in jail include simply disarming him, but only if you have rudimentary weapons training.
PS- Given the title, how many terrorists run around deserted streets with knives preying on families? (From what I've seen, they want to do something with explosives where they don't survive. If this was the case, it probably wouldn't matter if you shot the guy or not.) Wouldn't it more appropriatly refer to the war on crime?