The picture above of Oswald getting hit with the lrn bullet speaks more to the importance of shot placement then anything else I think. Often the old lrn police bullets barely broke 700 fps from 4" guns.
I'm leery of trying to draw widespread conclusions based on reports of handgun stops from torso shots. The round that hit Oswald destroyed several vital organs. Other fellas have been shot in non vital locations but dropped to the ground as readily. Both are "one shot stops" and counted to attest to the ability of one brand of bullet versus another. Hard to rely on that.
Most useful I think is to picked a good and reliable bullet, match it to the job at hand, and practice. Good shot placement makes up for alot.