Thanks for that link, that is pretty interesting and I can't honestly say I know exactly what the law is where I live (in Australia, but not in the state that gets a special mention in that article). And absolutely, if I happened to have access to a lethal weapon and I was sufficiently fearful I might well be tempted to use it on an intruder even well before they posed an immediate threat. But if I really were responsible for taking an intruder's life and the courts determined that they were never a realistic threat to anyone, nor was there any good reason for me to believe they were (e.g. I had a clear view of them, could see that had no weapon, and they weren't acting in any sort of hostile manner), I'd fully expect to go to jail for it.