California Code, Penal Code - PEN § 6127.3

(a) In connection with duties authorized pursuant to this chapter, the Office of the Inspector General may do any of the following:

(b) Any subpoena issued under this chapter extends as process to all parts of the state and may be served by any person authorized to serve process of courts of record or by any person designated for that purpose by the office.  The person serving this process may receive compensation as is allowed by the office, not to exceed the fees prescribed by law for similar service.