It's always a bad assumption to characterize a group of people and make them what you think they are. Or what maybe a lot of them are doing. This issue gets handled head on here and it doesn't take any prisoners. The movie is made for you to think (especially if you're Italian or have followed some of the things that went down in that country) about incidents. Like the one depicted in another movie (Diaz: Don't clean up this blood). It's only a small fraction in this movie here, but that issue is spoken of too.
So while you might have a pre-arranged picture that suits the title of the movie, there is more going on. Of course the movie would not be authentic if it didn't involve said cops. But the question always remains, why it came to that fact (for some of them). If you're open minded this might appeal to you and you might see that there are some differences