As above, if I am not threatened, and I am not a LEO, then I do nothing. With the laws these days, shoot someone for robbing a store just because he has a gun and will use it and is breaking every law, he will win in court and who shoots him will be in jail... unless maybe you are in TX, not even sure about that.
But most states will protect the shooter if his/her life is in danger.
All that said, who knows what we really do when it comes time. Just hope its the right thing.
(that was a awful answer
)
"Any Government big enough to give you everything you want, is strong enough to take everything you have...." - Thomas Jefferson.