Cal. Penal Code § 241.4

An assault is punishable by fine not exceeding one thousand dollars ($1,000), or by imprisonment in the county jail not exceeding six months, or by both. When the assault is committed against the person of a peace officer engaged in the performance of his or her duties as a member of a police department of a school district pursuant to Section 38000 of the Education Code, and the person committing the offense knows or reasonably should know that the victim is a peace officer engaged in the performance of his or her duties, the offense shall be punished by imprisonment in the county jail not exceeding one year or by imprisonment pursuant to subdivision (h) of Section 1170.