Browsing wikipedia I found the concept of "Civilian police oversight agency" [1]. For example the City of Minneapolis has the "Office of Police Conduct Review"

Browsing wikipedia I found the concept of "Civilian police oversight agency" [1]. For example the City of Minneapolis has the "Office of Police Conduct Review" [2]. So it looks like the institutions you are alluding to already exist, they probably need to be empowered more somehow. [1] https://en.wikipedia.org/wiki/Civilian_police_oversight_agency#List_of_places_with_civilian_oversight https://en.wikipedia.org/wiki/Civilian_police_oversight_agen... [2] http://www.minneapolismn.gov/civilrights/policereview/ http://www.minneapolismn.gov/civilrights/policereview/