Broke into the wrong home...scene from America, armed mom stops violent criminal with her gun....

[2aguy]

It is hard to imagine why she would actually to have shoot and kill the robber?
Its possible he was deranged or something, but not likely.
Normally robbers try to flee once discovered, and certainly would have been intimidated by her gun.
So I doubt there was a need to pull the trigger.

Do you know exactly how it happened?

Were you there?