As far as I am concerned the 9mm is on the lower edges of an effective man stopper. I believe many agencies went to the 9mm not only because the FBI using it started a cascade of agencies changing from wheel guns to 9mms but because smaller men and women could easier control the recoil over the .357 mag. For most of my law enforcement career I carried a mod 686 S&W .357 Mag in uniform and a .45 1911 in plain clothes. Now as a civilian I carry a .40 S&W most of the time because of it's size and because it has more punch than a 9mm or God forbid a .380. Just before I retired my agency switched over to the .357 Sig which is superior to the 9mm. So far as LE officers not being competent with their firearms, I can't speak for other agencies but my agency demanded better than competency and we qualified twice a year during daylight hours, once at night and once under winter weather conditions and at one time our course of fire went back to 50 yards with the handgun, so you can't paint every LE agency with the same brush. I am 70 years old and I must still qualify once a year to maintain my national carry privileges as a retired LE officer and normally I qualify with both a .357 Mag wheel gun and my .40 S&W Kahr MK 40, and a couple of months ago I fired a 97 percent on qualification. That said, most officers never get into a fire fight and a fire fight is under conditions that are much different than firing a qualifying score. It is because getting into firefights is not the norm and no matter how much you train, nothing can really prepare you for a fire fight until you are in one. So making a blanket statement that most law enforcement officers can't shoot straight is over simplified and very misleading. How many bullets go off into who knows where in war fired by professional soldiers. The fog of combat is far different from the controlled circumstances of the firing range, no matter how realistic and how much stress the instructors out on those firing the course.