It is a bad strategy to shoot an unarmed person.
It is a worse strategy to allow a woman to be beaten or killedand do nothing.
In Utah I would have been justified with Deadly force...It wouldn't have mattered Armed or Not.
2-402. Force in defense of person -- Forcible felony defined.
(1) A person is justified in threatening or using force against another when and to the extent that he or she reasonably believes that force is necessary to defend himself or a third person against such other's imminent use of unlawful force. However, that person is justified in using force intended or likely to cause death or serious bodily injury only if he or she reasonably believes that force is necessary to prevent death or serious bodily injury to himself or a third person as a result of the other's imminent use of unlawful force, or to prevent the commission of a forcible felony.
(3) A person does not have a duty to retreat from the force or threatened force described in Subsection (1) in a place where that person has lawfully entered or remained, except as provided in Subsection (2)(c).
(4) For purposes of this section, a forcible felony includes aggravated assault,..."