You have the right to record police in public, federal court rules
Police actively try to resist this.I saw something really interesting when getting pulled over by the police a while back (on a boat). When they saw us recording them while they were writing a ticket, they shined a bright flashlight at our camera so that it would ruin the exposure and not capture anything useful. They were very deliberate about this and it was quite effective.Something does seem wrong about police in public not wanting to be recorded while doing their (taxpayer funded) job and holding extra power over the citizen (a police's word in court generally comes with a special authority).