California Code, Penal Code - PEN § 925a

The grand jury may at any time examine the books and records of any incorporated city or joint powers agency located in the county. In addition to any other investigatory powers granted by this chapter, the grand jury may investigate and report upon the operations, accounts, and records of the officers, departments, functions, and the method or system of performing the duties of any such city or joint powers agency and make such recommendations as it may deem proper and fit.

The grand jury may investigate and report upon the needs of all joint powers agencies in the county, including the abolition or creation of agencies and the equipment for, or the method or system of performing the duties of, the several agencies. It shall cause a copy of any such report to be transmitted to the governing body of any affected agency.

As used in this section, “joint powers agency” means an agency described in Section 6506 of the Government Code whose jurisdiction encompasses all or part of a county.