NYPD police gun discharge study
Pdf here. A number of interesting results. A majority of shots were fired at 1-2 yards, and hit rate was only 43% at that range (both results not uncommon, actually). At 3-7 yards this drops to 23%, then at 8-15 yards rises again to 40%. Perhaps the officers have the ability to take better aim there, or maybe it's a fluke of the small sample size,
What's very interesting is that only 45% occurred on duty, in uniform. 36% were, I assume, undercover, and 18% off duty and out of uniform. From the individual reports, many of the undercover shootings did not involve a gunfight with the suspect: the officer was investigating one event when he saw an unrelated crime taking place (in one case, bank robbers had the bad luck to try to car-jack an undercover officer).
32 shootings were dog-related, 28 involving pit bulls.
On the less pleasant side, 26 accidental discharges, which fortunately resulted in no deaths but several injuries.