You'd be surprised how many videos...*very* graphic videos...there are on youtube showing police responses to domestic calls (and other calls). Many of them feature a guy on meth...or with a schizophrenia diagnosis...who decides to point a gun at cops or rush at them with a knife/machete.
Also...I worked in a big city ER for years. I've seen more murder victims than I care to remember. That counts for something.
The videos wouldn’t -exactly- be a surprise to me.
And if I watch ER and House a lot, I guess I am almost an expert on medicine.
Bottom line, as a cop, you are not allowed to open fire on someone for simply holding a pistol down at their side. Even if you are actually dealing with the actual people and not a mistaken address. And wrong addresses are a daily fact of life in cop world.
He got scared and overreacted and forgot all his training. The county will pay out the nose, and he will be lucky to avoid prosecution.