I don't understand why ANY domestic police agency should have, carry or use full automatic weapons. I suppose it is the desire to have bigger and badder toys than the other side. How about we start issuing area fire weapons (grenade launchers, mortars, howitzers, Reaper drones with Hellfire missles, etc) so the cops will be able to outgun the bad guys.
From what I have seen, frankly most LEO's would have a hard time hitting the broad side of a barn from the inside3. Maybe they "qualify" annually, but it seems that the occurence of "we fired 40 rounds and hit the miscreat twice (too bad about the 2-year old child we hit three blocks away, but we got the baed guy)" is more and more common. Even when I was an infantry office in the 'Nam, the best and most effective use for full auto fire was as supression fire to make the other guys keep their heads down. Single round aimed fire is far more effective than "pray and spray".
Frankly, I think the idea of police marksmanship became an oxymoron with the advent of the "wondernine" high cap plastic pistol. When the officer had a 6-round revolver with a pouch of speedloaders, he had to make his shots count.
The worst firearms discipline I regularly see is by LEO's; they ignore the four rules, do not control the muzzle, and get the fur up on their backs (and look for payback opportunities) if their failings are brought to their attention. Obviously, this does not apply to ALL LEO's, but you all know the offenders in your own agencies.
And along the same rant - why do tax collectors feel they deserve to be armed? What earthly justification is there for the IRS, BATF, Customs, etc to be armed? Isn't that what the federal police agencies (FBI, Federal Marshals Service, Postal Inspectors) are for?