I remember reading many years ago that one of the designers of the Sykes Fairbairn commando knife served as a police captain in the orient. One of his officers confronted a knife-wielding thief who was hopped up on narcotics. The officer emptied a M1911 into the perpetrator but the theif ultimately had to be pistol-whipped into submission. For those not readily up on their handgun know-how the .45 is generally a gun that will take grown men off their feet.
Research into the episode convinced Fairbairn that only a shot that hit the heart, brain, spinal column or femurs would be reasonably certain to subdue an opponent.
Now these would require very accurate shots--against moving targets--in the highest of all high stress situations.
Perhaps one *might* say if the officer was defending only him/herself they should attempt minimal force (I wouldn't but an "assumed risk" argument could be made at DU or other suitable asylum), but to ask a police force to take those chances when defending the citizenry?
Unconscionable.