Amazingly, that is also the case here in the UK. Common Law states that you can use 'appropriate' force if you feel that your (or someone else's) life is in danger. However, it is all about being able to justify your actions. There was a farmer here who got prosecuted sucessfully when he was burgled by a bunch of youths and he shot one of them. The only problem was that the kid was fleeing and got shot in the back, so the murdering farmer's 'self-defence' case held no water.