The juvenile court may not dismiss dependency petition at the detention hearing. At the detention hearing, the juvenile court sua sponte dismissed a petition alleging domestic violence. The department filed a writ petition, challenging the decision to dismiss the petition and return the minor to her mother. The appellate court granted the writ petition. Barring exceptional and exigent circumstances not present here, the juvenile court has no authority to dismiss a dependency petition at the detention hearing. The statutory scheme envisions that the sufficiency of evidence will be addressed at the adjudication hearing, not at the detention hearing. The petition was not insufficient on its face. Even if the petition had been insufficient on its face, there was no compelling reason that the issue demanded resolution without formal notice and a full opportunity to be heard.