California Code, Penal Code - PEN § 629.80

No otherwise privileged communication intercepted in accordance with, or in violation of, the provisions of this chapter shall lose its privileged character.  When a peace officer or federal law enforcement officer, while engaged in intercepting wire or electronic communications in the manner authorized by this chapter, intercepts wire or electronic communications that are of a privileged nature he or she shall immediately cease the interception for at least two minutes.  After a period of at least two minutes, interception may be resumed for up to 30 seconds during which time the officer shall determine if the nature of the communication is still privileged.  If still of a privileged nature, the officer shall again cease interception for at least two minutes, after which the officer may again resume interception for up to 30 seconds to redetermine the nature of the communication.  The officer shall continue to go online and offline in this manner until the time that the communication is no longer privileged or the communication ends.  The recording device shall be metered so as to authenticate upon review that interruptions occurred as set forth in this chapter.