This webpage contains several interesting reports on types of police oversight.
There are 2 articles that are overviews of police oversight and then several publications that review oversight at individual police departments.
Recent Reports – National Association for Civilian Oversight of Law Enforcement
— Read on www.nacole.org/recent_reports
Oversight Hearing on Policing Practices | Cato Institute
— Read on www.cato.org/testimony/oversight-hearing-policing-practices
The Chicago Police Board is an independent civilian body that oversees certain activities of the Chicago Police Department. The Board’s powers and responsibilities include deciding disciplinary matters involving police officers and nominating candidates for Superintendent of Police to the Mayor.
— Read on www.chicago.gov/city/en/depts/cpb.html
Civilian Office of Police Accountability
— Read on www.chicagocopa.org/