Cal. Penal Code § 71

(a) Every person who, with intent to cause, attempts to cause, or causes, any officer or employee of any public or private educational institution or any public officer or employee to do, or refrain from doing, any act in the performance of his duties, by means of a threat, directly communicated to such person, to inflict an unlawful injury upon any person or property, and it reasonably appears to the recipient of the threat that such threat could be carried out, is guilty of a public offense punishable as follows: (1) Upon a first conviction, such person is punishable by a fine not exceeding ten thousand dollars ($10,000), or by imprisonment pursuant to subdivision (h) of Section 1170, or in a county jail not exceeding one year, or by both that fine and imprisonment. (2) If the person has been previously convicted of a violation of this section, such previous conviction shall be charged in the accusatory pleading, and if that previous conviction is found to be true by the jury, upon a jury trial, or by the court, upon a court trial, or is admitted by the defendant, he or she is punishable by imprisonment pursuant to subdivision (h) of Section 1170. (b) As used in this section, “directly communicated” includes, but is not limited to, a communication to the recipient of the threat by telephone, telegraph, or letter.