California Code, Business and Professions Code - BPC § 7521

(a) Crime or wrongs done or threatened against the United States of America or any state or territory of the United States of America.

(b) The identity, habits, conduct, business, occupation, honesty, integrity, credibility, knowledge, trustworthiness, efficiency, loyalty, activity, movement, whereabouts, affiliations, associations, transactions, acts, reputation, or character of any person.

(c) The location, disposition, or recovery of lost or stolen property.

(d) The cause or responsibility for fires, libels, losses, accidents, or damage or injury to persons or to property.

(e) Securing evidence to be used before any court, board, officer, or investigating committee.

For the purposes of this section, a private investigator is any person, as defined in Section 7512.3, acting for the purpose of investigating, obtaining, and reporting to any employer, or an agent designated by the employer, information concerning the employer's employees involving questions of integrity, honesty, breach of rules, or other standards of performance of job duties.

This section does not apply to a public utility regulated by the Public Utilities Commission, or its employees.