I'll add: While it's clearly better to be alive than dead.. It's also true that an 8 x 12 cell isn't much of a life.
I talked about Disparity of Force earlier. And there was sufficient basis in the article that I'm satisfied that was present: i.e. A healthy adult male versus an elderly woman. She has little or no recourse against him on a physical level.
The laws vary widely depending on where you live, but if (you) adhere to the standard
"...immediate and otherwise unavoidable danger of death or grave bodily harm to the innocent...", then (you're) on fairly solid ground. Almost no matter where you may be.
Immediate? - You can't shoot him because of what he might do in the future. And you can't shoot him because of something he already did. In this case, I think we can all agree on "Immediate": He was there, in the room (and nearly naked, AAMOF), and he was following her through the house.
Unavoidable? – A bit less clear whether or not she could have gotten away. We don’t know if the intruder was blocking her exit, or if should could have left unseen/unmolested. The article does not tell us whether she could have escaped, despite the man following her. But as a point of law - where she lives she does not have to retreat in her own domicile.
Danger of Death or Bodily Harm? Let’s quote the article:
Maloney told police that a white man burst through a rear door that was unlocked. She told police she had never seen him before, and had no idea why he was there.
Lt. Tom Collins of the Newport Police Department says the man backed Ms. Maloney through the house, and she told the subject several times to leave, but he did not. She was able to get a firearm out of a drawer, fired two shots, hitting the man once. The man has not been identified and was pronounced dead at the scene. Investigators are working to confirm his identity.
A neighbor captured surveillance video where flashes can be seen at the time of the incident. Click the video above to see an excerpt from the surveillance video.
An autopsy of the man is planned, and police hope it may shed some light on the condition the man was in at the time of the shooting.
Lt. Tom Collins of Newport Police told Fox 19, "Obviously she felt that her life was in danger, and she took what action she felt was necessary."
…so we have a nearly naked man, entering an old woman’s house, and following her through the place as she tried to back away. Now, as explained earlier given the ‘Disparity of Force’ concept: The man need not be armed for there to be DoF when he puts himself up against an old woman. And (more to the point), the Police agree.
Innocent? - Yes: She was in her own home, peacefully minding her own business, when a near~naked man burst through the back door and began stalking her through the house.
So I would say the standard is met.
****
Police will talk also about “Ability, Opportunity, and Jeopardy”. So let’s visit that:
Ability: It’s clear that an old woman stands little chance against a healthy adult male. Check
Opportunity: He’s in the house, where he shouldn’t be. Check
Jeopardy: He’s nearly naked,
and stalking her as she’s attempting to back away. Check, and Double Check.