California Code, Family Code - FAM § 3140

(a) Subject to subdivisions (b) and (c), before granting or modifying a custody order in a case in which one or both parents of the child have not appeared either personally or by counsel, the court shall require the parent, petitioner, or other party appearing in the case to submit a certified copy of the child's birth certificate to the court. The court or its designee shall forward the certified copy of the birth certificate to the local police or sheriff's department which shall check with the National Crime Information Center Missing Person System to ascertain whether the child has been reported missing or is the victim of an abduction and shall report the results of the check to the court.

(b) If the custody matter before the court also involves a petition for the dissolution of marriage or the adjudication of paternity rights or duties, this section applies only to a case in which there is no proof of personal service of the petition on the absent parent.

(c) For good cause shown, the court may waive the requirements of this section.