LEO's carry rounds designed to penetrate barriers. Those same rounds have a hard time stopping in a body, it's just physics. Rounds which will stop in a body are either light bullets, or slow bullets. JHP's help immensely in stopping the round in the body - converting kinetic energy of the bullet first to deforming the bullet, then forcing much higher resistance as the bullet travels through the body, which is why LEO's use them - not for making a larger wound and 'larger blood channels' although they are probably fine with that.
I'm not a cop, I'm a civilian and I use non +P JHP's in most things I carry. I'm not defeating barriers, if there is a barrier there it probably suits me fine. Also my shot is much more likely to be frontal, and running in any other direction other than towards me isn't a shooting offense.