The Ninth Circuit has found that an officer violates the First Amendment if he makes a decision to book an arrestee (rather than cite and release) in retaliation for the arrestee’s exercise, after the moment of arrest, of First Amendment rights, even if the arrest is supported by probable cause and the booking decision is authorized under state law.  CSAC is supporting the city’s rehearing petition with a letter drafted by Peter Keith in the San Francisco City Attorney’s Office.