The office of the Auditor was created by the State Legislature under Article II of the State Constitution (Gov. Code Section 24000-24009) and the duties are defined in Gov. Code Sections 26900-26923 as follows:

• Audit of County functions and controls
• Audit of accounts of County debtor
• Keep accounts current with Treasurer
• Examine Treasurer's books
• Return erroneous payments
• Maintain and destroy records
• Act as the Chief Accounting Officer of the County
• Allocate advalorem property taxes
• Prescribe and exercise general supervision over accounting forms and methods of keeping accounts of all officers, departments, and institutions under Board control and all districts whose funds are in the County treasury
• In addition to accounts required by law, maintain accounts and statistics and prepare such reports therefrom as the Board may deem necessary for its information and use in the management and control of the operations of the County and the district whose funds are in the County treasury

The function of the Controller was added to the Auditor by the Board of Supervisors with Resolution #64-83. The authority and duties are defined in Government Code Sections 26881-26886 as follows:

• Audit accounts and records under control of the Board; If fraud or gross negligence, file with the District Attorney
• Prepare reports for the Board upon their request
• Control audits of independent Special Districts