Surprisingly the character in the movie is so obsessed with video recording on both side of the law. The movie is executed in a rather fresh way in the movie industry and genre and that is one of the reason (beside Jake Gyllenhaal) I choose to watch this instead.
If you still have no idea how it is like, just imagine Paranormal Activity from police point of view. It started at a very slow pace and it stay that way till the end of the movie. To me it seems to be "plotless" or at least doesn't have a strong plot to have a movie in the first place.
The movie focuses on brotherhood among the police / partner and about their life behind the blue uniform and golden badge. It also portrait how a police life like on a day to day routine with their rounding and busting to keep the street clean. I know it has been highly rated, but personally I've seen much better version of caught on camera clip on internet and Most Shocking is one of it.