If nations can kill in defense of property so should the citizens that live there.Citizens look up to their governments as examples of how they should behave and if the government is a violent one then it is likely the citizens will be as well.This is just natural the way that all people behave.
I think people should be able to kill in defense of their property if their life or someone else's life is in danger from the person invading their property. In all cases, people should be able to defend themselves and their belongings. Criminals should not be able to break the law without the possibility of immediate consequences. This might make people think twice before they commit this kind of crime.