So, the thing I have seen so far in this thread, that disturbs me greatly: there is the automatic assumption that for cops, doing good things does not make them good people. There seems to be a major prejudice that assumes that because someone is a police officer, their cop-ness overshadows the things they do.
This, to me, indicates a problematic and unfair assumption about police, and which reflects something that you can learn easily from any intro-to-psych course: when people have a good first impression, resulting bad behavior is seen as a mistake. When people have a bad first impression, resulting good behavior is seen as what is accidental.
The sentiment I gather so far here is that few people here think cops can possibly be good people. It is disappointing and antisocial to assume people are so awful as all that. It means you don't see cops as people but as enemies. The problem is that each and every one of us relies on police, and if we do not want to accept the need for a division of labor to exert society's rules, then the issue is not the police or the people in the uniform, and we should not vilify them. We should just, in that case, do away with the uniform. Vilifying them solves nothing but perverting those who we expected to do a job into an enemy that we ourselves armed and trained.