The Office of the Inspector General oversees the state's correctional system through audits, special reviews, inspections, investigations, and contemporaneous monitoring of the Department of Corrections and Rehabilitation. Although the duties required of the Inspector General's Office are complex, its mission is clear: to protect public safety by safeguarding the integrity of California's correctional system.

The Office of the Inspector General's Bureau of Audits and Bureau of Criminal Investigations promote accountability through objective, independent audits, special reviews, inspections including medical inspections, and investigations of California's correctional system. As a result of the audits, reviews, inspections, and investigations, the Inspector General provides impartial analysis and policy recommendations to the Governor, the Legislature, correctional administrators, and the public. The Office of the Inspector General is mandated to perform baseline audits of correctional institutions and wardens and to evaluate the qualifications of warden and superintendent candidates whose names have been submitted by the Governor.

Established within the Office of the Inspector General is the Bureau of Independent Review, which is primarily responsible for monitoring all significant internal affairs investigations and disciplinary actions conducted by the Department of Corrections and Rehabilitation to ensure they are performed in a timely and professionally sound manner through the oversight of those investigations and the employee discipline process. With regional offices throughout the state, the Bureau also provides contemporaneous oversight monitoring of all deadly force incidents, certain custodial death incidents, and other significant critical incidents. As required by statute, the Bureau's monitoring activities are reported semi-annually to the public on the OIG website as internal affairs investigations are conducted.

In addition, the Public Safety and Offender Rehabilitation Services Act of 2007, Chapter 7, Statutes of 2007, created the California Rehabilitation Oversight Board (Board) within the Office of the Inspector General. The Board's mandate is to examine the Department of Corrections and Rehabilitation's various mental health, substance abuse, educational, and employment programs for inmates and parolees. The Board meets quarterly to recommend modifications, additions, and eliminations of offender rehabilitation and treatment programs. The Board also submits biannual reports to the Governor, the Legislature, and the public to convey its findings on the effectiveness of treatment efforts, rehabilitation needs of offenders, gaps in offender rehabilitation services, and levels of offender participation and success.