California Code, Penal Code - PEN § 936.5

(a) When requested to do so by the grand jury of any county, the presiding judge of the superior court may employ special counsel and special investigators, whose duty it shall be to investigate and present the evidence of the investigation to the grand jury.

(b) Prior to the appointment, the presiding judge shall conduct an evidentiary hearing and find that a conflict exists that would prevent the local district attorney, the county counsel, and the Attorney General from performing such investigation.  Notice of the hearing shall be given to each of them unless he or she is a subject of the investigation.  The finding of the presiding judge may be appealed by the district attorney, the county counsel, or the Attorney General.  The order shall be stayed pending the appeal made under this section.

(c) The authority to appoint is contingent upon the certification by the auditor-comptroller of the county, that the grand jury has funds appropriated to it sufficient to compensate the special counsel and investigator for services rendered pursuant to the court order.  In the absence of a certification the court has no authority to appoint.  In the event the county board of supervisors or a member thereof is under investigation, the county has an obligation to appropriate the necessary funds.