Pen. Code, § 636

(a) Every person who, without permission from all parties to the conversation, eavesdrops on or records, by means of an electronic device, a conversation, or any portion thereof, between a person who is in the physical custody of a law enforcement officer or other public officer, or who is on the property of a law enforcement agency or other public agency, and that person’s attorney, religious adviser, or licensed physician, is guilty of a felony punishable by imprisonment pursuant to subdivision (h) of Section 1170.

(b) Every person who, intentionally and without permission from all parties to the conversation, nonelectronically eavesdrops upon a conversation, or any portion thereof, that occurs between a person who is in the physical custody of a law enforcement officer or other public officer and that person’s attorney, religious adviser, or licensed physician, is guilty of a public offense. This subdivision applies to conversations that occur in a place, and under circumstances, where there exists a reasonable expectation of privacy, including a custody holding area, holding area, or anteroom. This subdivision does not apply to conversations that are inadvertently overheard or that take place in a courtroom or other room used for adjudicatory proceedings. A person who is convicted of violating this subdivision shall be punished by imprisonment pursuant to subdivision (h) of Section 1170, or in a county jail for a term not to exceed one year, or by a fine not to exceed two thousand five hundred dollars ($2,500), or by both that fine and imprisonment.

(c) This section shall not apply to any employee of a public utility engaged in the business of providing service and facilities for telephone or telegraph communications while engaged in the construction, maintenance, conduct, or operation of the service or facilities of that public utility who listens in to conversations for the limited purpose of testing or servicing equipment.