From reading the article which you linked, it reported that there were two handguns founds at the crime scene. It reported that police observed upon entering the house; "They also observed two handguns and spent brass cartridges on the ground."
The woman arrested, Michelle Gable, had a gunshot wound to the arm.
Joseph Gable was alive when police arrived but died later. Sunday Bennett was found dead at the scene with a gunshot wound to the chest.
Perhaps Mr. Gable tried to defend himself by shooting Michelle Gabe, but failed to hit center of mass and only hit her arm.
In a chaotic, emotionally charged life and death situation, it is so difficult to make good decisions. I presume that a split second might have made a difference here, if Mr. Gable had earlier realized that he was in deadly danger and possessed the skill to deliver two shots to center of mass before he was incapacitated and mortally wounded (assuming he did shoot Michelle Gable in the arm).
NRA Life Member - Orange Gunsite Member - NRA Certified Pistol Instructor
"When plunder becomes a way of life for a group of men living together in society,
they create for themselves in the course of time a legal system that authorizes it and a moral code that justifies it." Frederic Bastiat