Cal. Bus. & Prof. Code § 7582.1

(a) A private patrol operator, or operator of a private patrol service, within the meaning of this chapter is a person, other than an armored contract carrier, who, for any consideration whatsoever:
Agrees to furnish, or furnishes, a watchman, guard, patrolperson, or other person to protect persons or property or to prevent the theft, unlawful taking, loss, embezzlement, misappropriation, or concealment of any goods, wares, merchandise, money, bonds, stocks, notes, documents, papers, or property of any kind; or performs the service of a watchman, guard, patrolperson, or other person, for any of these purposes.
(b)
1. (1) A person licensed as a private patrol operator only may not make any investigation or investigations except those that are incidental to the theft, loss, embezzlement, misappropriation, or concealment of any property, or any other thing enumerated in this section that they have been hired or engaged to protect, guard, or watch.
2. (2) Paragraph (1) shall not apply to any federally recognized tribe performing investigative functions within the jurisdiction of a federally recognized tribe, consistent with federal or tribal law.
(c) An armored contract carrier within the meaning of this chapter is a contract carrier operating armored vehicles pursuant to California Highway Patrol and Public Utilities Commission authority.
(d) An armored vehicle guard within the meaning of this chapter is any person employed by an armored contract carrier who in the course of that employment carries a deadly weapon.
(e) A security guard or security officer, within the meaning of this chapter, is an employee of a private patrol operator, or an employee of a lawful business or public agency who is not exempted pursuant to Section 7582.2, who performs the functions as described in subdivision (a) on or about the premises owned or controlled by the customer of the private patrol operator or by the guard’s employer or in the company of persons being protected.
(f) A street patrolperson, within the meaning of this chapter, is a security guard or security officer employed by a private patrol operator who performs the functions described in subdivision (a) by street patrol service utilizing foot patrol, motor patrol, or other means of transportation in public areas, streets or public thoroughfares in order to serve multiple customers. “Street patrolperson” does not include management or supervisory employees of the private patrol operator moving from one customer location to another to inspect personnel or security guard or security officers.
(g) This section shall not limit the ability of a participating tribe to do either of the following:
1. (1) Perform for itself any services set forth in subdivision (a).
2. (2) Perform other investigative functions within the jurisdiction of a federally recognized tribe, consistent with federal or tribal law.