It is the intent of the Legislature in enacting this chapter to promote the safety and security of the public schools by restricting and conditioning the access of unauthorized persons to school campuses and to thereby implement the provisions of Section 28 of Article 1 of the California Constitution which guarantee all students and staff the inalienable constitutional right to attend safe, secure, and peaceful public schools. It is also the intent of the Legislature that the provisions of this chapter shall not be construed to infringe upon the legitimate exercise of constitutionally protected rights of freedom of speech and expression which may be expressed through rallies, demonstrations, and other forms of expression which may be appropriately engaged in by students and nonstudents in a campus setting.

As used in this chapter, with regard to a public school:

A person whose presence or conduct on school grounds violates another provision of law may be punished for that violation, regardless of whether he or she was registered pursuant to this chapter at the time of the violation; but no punishment shall be imposed contrary to Section 654.