It also varies dramatically between US states. If you shot a burglar in your house with an AR-15 in Florida the local DA might give you a medal. In New Jersey they would arrest you just for having the AR-15, and then likely charge you with murder.

(I'm not commenting on the morality of either state's laws; just pointing out that US states differ widely on gun laws.)

[Edit: I originally said California instead of New Jersey. NJ's laws are stricter but it appears that the vast majority of states allow much leeway when in your own home, so I might even be wrong about NJ.

https://en.m.wikipedia.org/wiki/Stand-your-ground_law

]

FWIW, even before the advent of the recent wave of "stand your ground" laws, there was an older legal principle, that was very widely held, called "castle doctrine"[1] which comes into play in terms of killing a home intruder. The details still vary from state to state, but AIUI, many locales hold to a form of castle doctrine such that if you kill an invader who is actually in your home, you would be unlikely to be charged with murder.

[1]: https://en.wikipedia.org/wiki/Castle_doctrine

That would prove very handy against vampires. Could they resist an invite to your home?