(a) Any specified drug offender who, at any time, comes into any school building or upon any school ground, or adjacent street, sidewalk, or public way, unless the person is a parent or guardian of a child attending that school and his or her presence is during any school activity, or is a student at the school and his or her presence is during any school activity, or has prior written permission for the entry from the chief administrative officer of that school, is guilty of a misdemeanor if he or she does any of the following:

1. (1) Remains there after being asked to leave by the chief administrative officer of that school or his or her designated representative, or by a person employed as a member of a security or police department of a school district pursuant to Section 39670 of the Education Code, or a city police officer, sheriff, or a Department of the California Highway Patrol peace officer.
2. (2) Reenters or comes upon that place within seven days of being asked to leave by a person specified in paragraph (1) of subdivision (a).

3. (3) Has otherwise established a continued pattern of unauthorized entry.

   This section shall not be utilized to impinge upon the lawful exercise of constitutionally protected rights of freedom of speech or assembly, or to prohibit any lawful act, including picketing, strikes, or collective bargaining.

(b) Punishment for violation of this section shall be as follows:

1. (1) Upon a first conviction, by a fine not exceeding one thousand dollars ($1,000), by imprisonment in the county jail for a period of not more than six months, or by both that fine and imprisonment.
2. (2) If the defendant has been previously convicted once of a violation of any offense defined in this chapter or Section 415.5, by imprisonment in the county jail for a period of not less than 10 days or more than six months, or by both imprisonment and a fine not exceeding one thousand dollars ($1,000), and the defendant shall not be released on probation, parole, or any other basis until he or she has served not less than 10 days.
3. (3) If the defendant has been previously convicted two or more times of a violation of any offense defined in this chapter or Section 415.5, by imprisonment in the county jail for a period of not less than 90 days or more than six months, or by both imprisonment and a fine not exceeding one thousand dollars ($1,000), and the defendant shall not be released on probation, parole, or any other basis until he or she has served not less than 90 days.

(c) As used in this section:

1. (1) “Specified drug offender” means any person who, within the immediately preceding three years, has a felony or misdemeanor conviction of either:

   1. (A) Unlawful sale, or possession for sale, of any controlled substance, as defined in Section 11007 of the Health and Safety Code.
   2. (B) Unlawful use, possession, or being under the influence of any controlled substance, as defined in Section 11007 of the Health and Safety Code, where that conviction was based on conduct which occurred, wholly or partly, in any school building or upon any school ground, or adjacent street, sidewalk, or public way.
2. (2) “Continued pattern of unauthorized entry” means that on at least two prior occasions in the same calendar year the defendant came into any school building or upon any school ground, or adjacent street, sidewalk, or public way, and the defendant was asked to leave by a person specified in paragraph (1) of subdivision (a).
3. (3) “School” means any preschool or public or private school having any of grades kindergarten to 12, inclusive.
4. (4) “School activity” means and includes any school session, any extracurricular activity or event sponsored by or participated in by the school, and the 30-minute periods immediately preceding and following any session, activity, or event.