Until you have been in a situation similar to this, it's tough to understand the dynamics. People greatly greatly over-estimate their ability to think things through and behave rationally when under a tremendous amount of stress. We have been conditioned by movies and t.v. shows to believe things will happen thus and thus and I'll do this and that..... But really, the very least amount of confrontation you can manage in any sort of situation like this is best for everyone. No one should over-glorify being legally entitled to just jump in there and blast 'em. That's not usually how things work. Having to do something like this would be a tragedy for everyone concerned.
Amen!
When I conduct training and we discuss officer-involved shootings, I tend to mention that there are most often TWO "victims" of the shooting: The person who was shot, and the shooter. It is rare that an officer is able to continue working after an officer involved shooting., TV would have us believe it happens every day and that officers take a few days off, go to Disneyland, see a shrink, then come back ready to do it again. In reality, it's a lot tougher than that. Even if the officer comes back, most are out within a year or two ... they can';t do it anymore. Many more SHOULD get out, but they try and
cowboy up, much to their detriment and the detriment of their partners.
It is no simple thing to take a life for most people, and even in "good" shootings (where the justification was clear as day) it can be a difficult thing to process.
All of us can say, "If this happens, I will do XYZ ..." But, let me tell you right now, when it happens, unless you are well-trained, it will NOT happen the way you pictured it, and you will NOT feel the way you think you will. But, this is why police train to do what they do - and this includes shooting to a center of mass. Deviating from training and trying to shoot an extremity or do some fancy trick shootin' and knock the weapon from a guy's hand is guaranteed to distract and delay the response and likely result in a dead cop (or, in the case of a homeowner, a dead resident).
The bad guy with the gun may not have the conscience you and I have - he may not care a whit about killing you. Your conscience gives him the edge ... you need to train up and react in order to buy back the precious fraction of a second or so that can make the difference between life ... or death.