Penal Code section 148.6. makes it a crime to knowingly make a false accusation of misconduct against a peace officer. It is not a crime to knowingly make such an accusation against a firefighter, a paramedic, a teacher, an elected official, or anyone else. By protecting only peace officers, section 148.6 selectively prohibits expression because of its content. It therefore violates the First Amendment to the United States Constitution. Section 148.6, subdivision (a)(1) provides: "Every person who files any allegation of misconduct against any peace officer, . . . knowing the allegation to be false, is guilty of a misdemeanor." The law requires that the alleged misconduct occur during the course of the officer's official duties. ( San Diego Police Officers Assn. v. San Diego Police Department (1999) 76 Cal.App.4th 19 at p. 23.) Section 148.6, subdivision (a)(2) requires that the citizen-complainant be warned in boldface print of the criminal consequences of knowingly filing a false complaint. The written warning states: "YOU HAVE THE RIGHT TO MAKE a COMPLAINT AGAINST a POLICE OFFICER FOR ANY IMPROPER POLICE CONDUCT. CALIFORNIA LAW REQUIRES THIS AGENCY TO HAVE a PROCEDURE TO INVESTIGATE CITIZENS' COMPLAINTS. YOU HAVE a RIGHT TO a WRITTEN DESCRIPTION OF THIS PROCEDURE. THIS AGENCY MAY FIND AFTER INVESTIGATION THAT THERE IS NOT ENOUGH EVIDENCE TO WARRANT ACTION ON YOUR COMPLAINT; EVEN IF THAT IS THE CASE, YOU HAVE THE RIGHT TO MAKE THE COMPLAINT AND HAVE IT INVESTIGATED IF YOU BELIEVE AN OFFICER BEHAVED IMPROPERLY. CITIZEN COMPLAINTS AND ANY REPORTS OR FINDINGS RELATED TO COMPLAINTS MUST BE RETAINED BY THIS AGENCY FOR AT LEAST FIVE YEARS. IT IS AGAINST THE LAW TO MAKE a COMPLAINT THAT YOU KNOW TO BE FALSE. IF YOU MAKE a COMPLAINT AGAINST AN OFFICER KNOWING THAT IT IS FALSE, YOU CAN BE PROSECUTED ON a MISDEMEANOR CHARGE."