I'm suprised that no one mentioned that some departments buy guns spec'd from the factory with heavier trigger pulls, like 8lbs-ish.
But yes, police guns generally might see 100 rounds a year through the gun for yearly practice and qualification. Most cops, unless they are enthusiats, generally don't shoot any more than that. I have also seen some guns go into qualification every year with neglect. A regular civilian gun can see some neglect and it's ok because the gun stays in a safe or drawer, away from humidity and rain etc.... You can lube it once, take it to the range and leave it. Duty guns shouldn't be treated this way. These guns go outside into the environment every day. You will see wear on the outside from use, and they also get exposed to the elements like humidity, rain, dry sun etc.... If not properly cleaned and lubricated periodically they will have a little surface rust and some sand/dirt/carbon, but nothing major that couldn't be fixed with some extra TLC.