COPS is a horrible basis to use for anything. That's a television show where the police force invites the show to follow them around, sticks them with their best officers who know they are on camera the entire time, and try to act as according to the book as they possibly can for the camera. Also, the show is based on police compliance, so it's important for the police to always be shown in a good light in the show by the producers of the show. They typically always are shown to use the applicable force possible, and be very reasonable with whoever they were dealing with, no matter what.
In "real life," while many, probably the majority of U.S. police are decent people, there are enough of a number of them who are terrible people, or at least people who shouldn't not have that position of authority (ie. known psychological problems), which is a huge problem in this country when combined with the fact that a) prosecutors and police cover for those cops to the point in which many are still able to be police officers even while after abusing their authority, and b) there is often no departmental system in place that weeds out these kind of people that would help to avoid people getting hurt and killed. This makes sense, as police organizations weed out intelligent, balanced people that would make decent officers, either intentionally, or as a byproduct, while attracting personality types that want to feel a semblance of power, and are thus more likely to abuse it.
People have been saying this for a century, but because it was mostly the cries of the poor and/or minorities, not many listened. If it doesn't affect them personally, many people would rather ignore that some things might be happening that makes the world seem more unfair to others than they may have realized. Especially with the weird military/police worship or blind support for authority that many in this country have. It's only recently, with the advent of EVERYONE around having a video camera on their person, that a lot of people are starting to realize that, hey, perhaps all those anecdotes that were once ignored actually have some merit.