federally monitor/enforce police accountability

I am a citizen who feels powerless in the face of police officers who frequently use intimidation tactics and abuse their authority. I believe I am not alone. Countless law adults in our country have a disdain for police officers, because of the behavior of some of them. How can we feel we have a democratic system when we fear the enforcers of our own laws?
I encourage the creation of a new agency to monitor and protect the civil rights of everyday citizens against authority. This agency would investigate reported abuses of power before any court deliberation. Hopefully, the existence of such an agency would scare bad cops straight.
Police have power. In order to not abuse there power, they should be limited by the same fear of authority that burdens many good Americans.