Cal. Pub. Util. Code § 308.5
Persons employed as investigators and investigator supervisors by the commission, who are designated by the commission's executive director and approved by the commission, have the authority of peace officers, as specified in paragraph (5) of subdivision (a) of Section 830.11 of the Penal Code, while engaged in exercising the powers granted to or performing the duties imposed upon them in investigating the laws, orders, or regulations administered by the commission or commencing directly or indirectly any criminal prosecution arising from any investigation conducted under these laws. All persons herein referred to shall be deemed to be acting within the scope of employment with respect to all acts and matters set forth in this section.
Ca. Pub. Util. Code § 308.5