Apply For Bay Area Law Enforcement Jobs. The Contra Costa County Office of the Sheriff is hiring for sworn and civilian positions.The Office of the Sheriff is seeking men and women interested in an exciting and challenging career in dispatching. Prior experience is not required. The Contra Costa County Office of the Sheriff is seeking men and women interested in an exciting and challenging career in law enforcement. To apply, complete the Online Employment Application (we no longer accept paper applications), or call Sergeant Mitch Brouillette at (925) 809-7865. You may complete an on-line application at the Contra Costa Human Resources Department at 651 Pine St., 2nd Floor, Martinez, CA 94553. The investigation will include a preemployment polygraph examination; a Police Officer Standards and Training (POST) approved Personal History. Contra Costa cities that contract with the Sheriff for police services are generally able to fill vacancies faster than noncontract cities. Police Services will manage the security system software on both the District and campus levels.