Cal. Educ. Code § 49068.5

Upon the initial enrollment of a pupil in a public or private elementary school, or whenever an elementary school pupil transfers from one school district to another, transfers to an elementary school within the same district, transfers from one private elementary school to another, transfers from a private elementary school to a public elementary school, or transfers from a public elementary school to a private elementary school, the principal of the school that the child enters or to which he or she transfers is urged to check to see if the child resembles a child listed as missing by the bulletins provided by the Department of Justice pursuant to Section 14204 of the Penal Code.