There are dog police everywhere. I live in a nice suburban area in Melbourne, Australia. One time I got arrested and was in the van waiting to go to the police station. One of the three cops told me to come closer - out of sight of the cameras, I realised after - and spat in my face, jumper punched me and told me he was "running shit" and to do what he said.
Now fair enough I did break the law, this was a couple of years ago and I had shoplifted some bourbon. But I was respectful and thought the cop was way out of line.
Another time I was taken to the police station for an unrelated matter and interviewed. They made me leave my bag outside, and after they let me go I realised my bottle of Jagermeister had been taken from it.
I probably should have reported the first incident, but I was pretty shaken and just wanted to get out of there. I really don't think there is much point reporting things like that anyway. The two other cops with him would have stood with him, and it would have been my word against theirs.
I know most police are good guys, but I seem to have about a 50/50 chance of having a good or bad experience each time i run into them.