Even though we recognize that death may be the result of using such force, the purpose is not to kill the attacker; but to stop the threat. When the threat ends, you must stop firing, regardless of whether the attacker is alive or dead. Often, it will take more than one handgun round to physiologically force an attacker to stop; but every single round you fire must be justified under the law.
Thank you, B.R., for reminding us of this important principle of armed self-defense.
Even a casual remark such as "If someone attacks me I will shoot to kill", made years before, will come back to haunt you and be used against you should you ever have to use lethal force.
And the flip-side of that is that any remark that you didn't
shoot to kill, but deliberately tried to only wound
the subject, will similarly be used against you, on the grounds that if you had that
option, you probably had the option to not shoot at all
for the center of mass and shoot only
till the threat is neutralized. If the subject happens to die, that is merely an unfortunate side effect of having been stopped by bullets.