I can't believe that I am writing a post in the Ethics forum, as I usually try to avoid talk of ethics. But your link below is interesting and worth a response, so please consider my following comments.
When I was very young, my Mother always told me that if I got into trouble or lost, I should go to a policeman. She said that the police were there to protect me, and I should trust them. So why is this not what I taught my children? I taught my children to go to a neighbor, scream, and bang on the door for help, if they were in the neighborhood. I taught them to seek out an employee, if they were lost or frightened in a public place, as it is much more likely that an employee of a store is there to work, rather than there to make trouble. If my children were picked up by the police, I taught them to give my name, phone number, and address, then to say nothing else until I arrived.
The first real contact that I had with police was when I was 19, and the police had come to my home to arrest my younger brother. They said that he had gone AWOL after basic training in the Army and was being arrested and returned to the Army. But my brother had never been in the Army, and I said so. My Mother also said so. My brother, who was only 17 years of age, pointed out that he had hair half-way down his back, and so could not possibly have been in basic training, as the first thing they do is shave your head. Two witnesses plus evidence did not stop the police from taking him to jail and holding him for two days, until the Military Police showed up and proved his innocence. The fingerprints were wrong and the hair was a dead giveaway. Someone else had used his name and Social Security Number. This was the first time that I remember thinking that all policemen were not necessarily bright or trustworthy. The real tragedy was that this arrest stayed on his record all of his life. We did not realize this until a policeman called him a "draft dodger" 30 some years later, so every policeman that he dealt with, all of his life, had a prejudiced view of him because of that record.
The next time I dealt with the police, I was in my early 20's. I had worked the afternoon shift, gone home to change, and left again for my friend's wedding reception, hoping to see her. When I got there, it was over, and the bride's father was sweeping the floor of the hall they had rented. We talked for a few minutes, then I left for home. On the way home, I had to cross a railroad track that was diagonal to the road that I was on. As soon as I crossed it, my car started to fishtail wildly; I barely got it under control and off to the side. I was frightened and shaking when I saw a police car pull up behind me. The policeman shined his light in my window/face and asked me what I thought I was doing. I responded that I didn't know and got out of my car. Walking around the car, I could see that the driver's side tire was pointing straight, but the passenger's side front tire was pointing completely sideways. I had broken a tie rod and maybe more. So I asked the police if they could take me up the road to a restaurant, or someplace where there was a phone. (no cell phones then) The policeman responded, "We are not a taxi service." and left. So the police left a young woman on a deserted road in the middle of the night wearing high heels to walk to whatever could be found for help. Obviously, the idea of "serve and protect" was no longer their motto.
There are more examples and experiences that I could share, but I think that the above is enough. What I learned long ago is that the police were no longer there to protect me. Their job, as they state, is to uphold the law, which means to fight crime and look for bad guys. The problem is that what you look for will be what you find, and what you expect to see is what you will see. This idea was confirmed in an article that I read about divorce rates and police officers. It explained that policemen spend their entire careers looking for bad and evil, and it is difficult for them to turn that off and see innocence when they get home; hence, the high divorce rate.
I have no doubt that in their minds and hearts, policemen really believe that they are protecting the public, but in reality they are in a war on crime. Wars have casualties on both sides, so I am not surprised by the recent events. I was a young, white, naive female, with no criminal record, who was well dressed and well spoken -- innocence personified -- yet I still learned to distrust the police. What would a male, who was black, maybe not so well spoken, who lives in a rough part of town learn?
It is my personal belief that when a large group of people turn bad, it is the fault of bad governing, so I suspect that most of this tragedy is due to simple policy change and attitude change. I also expect that it will continue and worsen if someone does not wake up. We are actually creating criminals where they need not exist.