Another comment mentions training for center of mass, and I would assume that's what they do.
Let's say 80% of your shots constitute a "tight grouping", 20% being somewhere other than where you were aiming. Aiming for the middle of the body would likely mean you have a very high success rate of hitting your target individual. Aiming for the shoulder/leg/arm (each one harder than the last to hit) you are looking at a very low success rate of hitting your target. If you choose to use your weapon, I would hope you are confident you will hit your target and only your target.
When there is no margin left, fire to stop. (Which means in practice, often death.)
https://polisen.se/om-polisen/polisens-arbete/polisens-befog...
Are they fired close to the target, but far enough away to miss? Can this only be done if there is no one behind the target, are they shot into the sky? If so is their no danger of bullets hitting people falling back down? Or do they lose enough speed on the downward arc to be safe? Or is the chance of a warning shot hitting someone innocent so staggering low that it isn't worth worrying about?
So in theory its a kind idea. But hardly ever significant in practice?
https://www.cnn.com/2019/09/30/us/bronx-officer-shot-dead/in...
Against an already drawn gun and a trained as well as attentive officer? Do you have a source for that? I have a hard time believing that. Or is this the case after factoring into the US mentality of "there may not ever be any residual risk for a cop"?