The purpose of a Police Oversight Commission is to improve law enforcement performance and accountability. Police oversight models can vary. The National Association of Civilian Oversight of Law Enforcement (NACOLE) adopted a system (developed by Samuel Walker) which places police oversight bodies into one of three classifications:

Investigation-Focused Model:  involves routine, independent investigations of complaints against police officers, which may replace or duplicate police internal affairs processes, staffed by non-police civilian investigators.

Review-Focused Model: concentrates on commenting on completed investigations after reviewing the quality of police internal affairs investigations. Recommendations regarding findings, or requests for further investigations  may be made. A review board is composed of citizen volunteers who  may hold public meetings to collect community input and facilitate police-community communication.

Auditor/Monitor Model: focuses on examining broad patterns in complaint investigations including patterns in the quality of investigations, findings, and discipline. Further, in some cities, auditor/monitors may actively participate in or monitor open internal investigations. This model often seeks to promote broad organizational change by conducting systematic reviews of police policies, practices or training, and making recommendations for improvement.

More information: https://cops.usdoj.gov/RIC/ric.php?page=detail&id=COPS-W0861