As of now there is nothing unique that spawns on police situations. Other than the map related pioneer for police situations. What would be unique is if you change the Police Situation version of the pioneer rifle to a 308 conversion of it, since the rifle is based off the steyr scout rifle which has a 308 conversion. It would make the police situation pioneer more unique to the environment of DayZ.

Another way to add more unique loot for police situations is to reintroduce the long range scope for rail mounted weapons, you could make this spawn on both military and police dynamic events.