Where I used to work got robbed on a semi-regular basis, I've been shot at before and threatened with knives, bats, guns etc.
Yet, I have absolutely no sympathy for police officers who are overly aggressive. Yes, sometimes they do need to be that way in order to take down a perp before he causes any harm, BUT this kind of situation is more rare than you can imagine. At the same time, I've been arrested, and not told anything until after I was stripped naked and given prison clothes. Also, sitting in a cell for 4 days straight without getting out for a shower or anything is pretty shitty.
Now, the point is this, the police are people, but they are NOT citizens when they put on that badge. They are servants of the public. They are no longer allowed to expect the rights of the rest of us to apply to them. They are nonetheless given more rights in some ways than the rest of us.
This puts them in a special position of needing to be watched more than the general public due to the powers they possess.