Pen. Code, § 636.6

(a) (1) A person who manufactures, imports, markets, purchases, sells, or operates a signal jammer, unless authorized to do so by the Federal Communications Commission, is guilty of an infraction, punishable by a fine not to exceed five hundred dollars ($500) for a first offense.

(2) A second or subsequent violation of paragraph (1) is a misdemeanor, punishable by imprisonment in a county jail not exceeding year, by a fine not to exceed one thousand dollars ($1,000), or by both that fine and imprisonment.

(b) A person who operates a signal jammer in conjunction with the commission of a misdemeanor or felony is guilty of a misdemeanor, punishable by imprisonment in a county jail not exceeding one year, or by a fine not to exceed one thousand dollars ($1,000), or by both that fine and imprisonment.

(c) A person who willfully or maliciously uses a signal jammer to block state or local public safety communications, and who knows or should know that using the signal jammer is likely to result in death or great bodily injury and great bodily injury or death is sustained by any person as a result of that use, is guilty of a crime, punishable by imprisonment in a county jail not exceeding one year or pursuant to subdivision (h) of Section 1170.

(d) A conviction under this section requires forfeiture of the signal jamming device.

(e) This section does not apply to the authorized and lawful use of signal jammers by local or state law enforcement.

(f) For the purposes of this section, the following terms have the following meanings:

(1) “Signal jammer” means a device that intentionally blocks, jams, or interferes with authorized radio or wireless communications.

(2) “Public safety communications” means the systems, technologies, and methods used by emergency response agencies, including law enforcement, firefighters, and EMS, to communicate with each other.