I think that in part you're right, Az. It seems like the police aren't always at their most efficient. Take for example, last year at my school. Two cops are busy busting a couple of casual kids for smoking some pot, while not two blocks away, a brawl resulting in three hospitalizations is breaking out.
I disagree that they're quite often like this. It seems that you hear a lot about harassment and whatnot on the news, but most of the cops I have witnessed are very professional and know what they're doing. They know that one wrong move and the bad guy walks, so they watch their step. Of course, it's not so hard when you've got a police force for 900 000 people that has something like 30 murders a year (very good average.) I think that everyone makes mistakes, and when some people make them (police, President of the United States
) it seems to be a lot more public and looks more widespread then it actually is.