Cal. Pub. Util. Code § 99164
(a) When installing new security systems, a transit agency operated by an operator as defined in Section 99210 shall only purchase and install equipment capable of storing recorded images for at least one year, unless all of the following conditions apply:
(b) Notwithstanding any other provision of law, videotapes or recordings made by security systems operated as part of a public transit system shall be retained for one year, unless one of the following conditions applies: