. . . Or state officials.
Here is a new tactic that criminals might use.
Criminal: I like your shiny diamond ring, auntie. You hand it over, and I be nice. You not give it to me and I twist it off.
Woman of the House: That was a threat to my life, and I shoot your head off.
Justice Dept. State of HI: The shooter is charged with second degree murder. Reasoning, the criminal did not attack her. Taking a ring off a finger, even with the use of force, is not the threat of deadly bodily harm.
Here is another case criminals can win. Suppose your dog hears a burglar in the house, and the dog bites the thief's arm. With his free arm, he starts to beat the dog with a bat. Homeowner sees his/her beloved pet being struck and nearly killed. Homeowner shoots the thief. Guess who gets to sue the homeowner for the use of deadly force? The perp. Nothing in the law prevents this egregious misapplication of justice.
Case #1: If the ring-thief is killed, it's her word against the dead attacker's. Unless she incriminates herself, she only has to say she feared for her life. If the guy was armed, the fear is even more reasonable. If he lives, it's still he said - she said. Whether or not he intended to hurt her IF she complied, he still admitted hurting her was contingent on her resisting. Nothing in the law negates assault charges if the victim doesn't cooperate.

Case #2: The law allows residents to assume if someone is committing violence on their property and they were not invited, it's reasonable to assume the person is a threat. Whether or not lethal force is needed is not a factor. Private citizens are not trained police officers. We do not have to adhere to a continuum of force policy. If we can retreat, that's always an option, but inside your home, you have no DUTY to do so.
In all cases, use of lethal/deadly force is a life changing decision. Even if it's 100% justified, the gov't doesn't seek to prosecute, and the threat happened to be a serial killer, you still have to deal with PTSD and the guilt of having to take another person's life.
I'm not so concerned about what the state will do to me. I know deep down that I will only pull a trigger if it is my last option. Anyone who says otherwise ("I know where to dig the hole") should not offer anyone advice. Do what you want. I'll do the same.
Actually, there is something in the law that PUNISHES the state for "the egregious misapplication of justice." Aside from civil remedies for violating your Constitutional rights, state officials can also be prosecuted if their actions are that egregious. I'd refer you to the Kealoha case and all the people charged and convicted for their illegal abuse of power. That's not the norm, but safeguards do exist.