It's surprising that this still comes up. "Why didn't the officers just shoot him in the leg." Or the arm, or whatever.
After all, this worked perfectly well for The Lone Ranger or Roy Rogers....Why, they hardly ever killed anyone. And the bad guys, neatly shot through the leg (with nary an artery severed...) simply fell down and lay helplessly till the sheriff came along.
Alas, it doesn't work that way.
First, under the stress of a shooting incident, it's about average for officers to achieve 25% hits. That's hits on the entire bad guy... Not a particular body part.
I have written before as to why this is the case. Neurological and physiological and psychological effects come into play, and fine motor control goes out the window.
Second... Handguns are not particularly good stoppers. Even with modern ammunition, it's unusual for someone taking a peripheral hit to actually stop their attack. Under whatever stresses THEY are experiencing...They may not even be aware.
Handguns "stop" people by disrupting the central nervous system, or by causing them to bleed out. This may or may not be instantaneous, but likely not.
Third. The above "double tap and access" has been abandoned. Too many people getting shot during the "access" period as the bad guy was not "stopped".
Now, the paradigm is that one fires, center-mass of the target, until the threat is ended.
Period.