California Code, Welfare and Institutions Code - WIC § 342

(a) In any case in which a minor has been found to be a person described by Section 300 and the petitioner alleges new facts or circumstances, other than those under which the original petition was sustained, sufficient to state that the minor is a person described in Section 300, the petitioner shall file a subsequent petition.  This section does not apply if the jurisdiction of the juvenile court has been terminated prior to the new allegations.

(b) Unless otherwise provided by law, all procedures and hearings required for an original petition are applicable to a subsequent petition filed under this section.