California Code, Health and Safety Code - HSC § 11367.5

(a) Any sheriff, chief of police, the Chief of the Division of Law Enforcement, or the Commissioner of the California Highway Patrol, or a designee thereof, may, in his or her discretion, provide controlled substances in his or her possession and control to any duly authorized peace officer or civilian drug detection canine trainer working under the direction of a law enforcement agency, provided the controlled substances are no longer needed as criminal evidence and provided the person receiving the controlled substances, if required by the federal Drug Enforcement Administration, possesses a current and valid federal Drug Enforcement Administration registration which specifically authorizes the recipient to possess controlled substances while providing substance abuse training to law enforcement or the community or while providing canine drug detection training.

(b) All duly authorized peace officers, while providing substance abuse training to law enforcement or the community or while providing canine drug detection training, in performance of their official duties, and any person working under their immediate direction, supervision, or instruction, are immune from prosecution under this division.