The circumstances very. (not anything to do with how they break in) If someone is breaking into my home with what I perceive to be a will for violence against me or my family, they are at my mercy. I would not kill someone over property, but they'd damn sure be giving it back. (again at my mercy, though depending on things, they'd most likely get it [my mercy, with a stern warning]) These are situational decisions that are usually made quickly. Though I'm sure everyone here would agree, self defense is right, and a virtue at that. Those claiming that shooting an erratic driver = self defense, are mistaken on what self defense is.