you never need to kill someone who is stealing your china. or your tv. really.
you can get an alarm system, you can get a big dog, you can fortify the entries in your home. all of these things are excellent deterrants to break ins.
if you own a gun and you hear a noise in your house and you pull that gun out to go investigate you have already decided you are going to shoot someone. maybe it's not a conscious thought, but your finger is ready and you know it. it could be someone who is going to rape and kill your family but it's more likely the crack head kid down the street that saw your tv from the street one day.
most who will break into your home only want your stuff. will you kill for your stuff?
i would not.
But the fact of the matter is, the moment they decided to break into your house, etc, a person should have a right (at least, if we truly are free people and not modern day serfs, lol) to defend their lives, their family and friends lives, and property, using whatever force they deem necessary. Now does this mean you can capture and torture said criminal? heck no. but a person should not have to be in fear of the law for defending their property/belongings nor their lives/friends/families lives. The second a criminal breaks in, if any injury befalls them, it should be on their head alone and not the homeowners imho.