California Code, Family Code - FAM § 9328

(a) At the hearing the court shall examine the parties, or the counsel of any party not present in person.

(b) If the court is satisfied that the adoption will be in the best interests of the persons seeking the adoption and in the public interest and that there is no reason why the petition should not be granted, the court shall approve the adoption agreement and make an order of adoption declaring that the person adopted is the child of the adoptive parent. Otherwise, the court shall withhold approval of the agreement and deny the petition.

(c) In determining whether or not the adoption of any person pursuant to this part is in the best interests of the persons seeking the adoption or the public interest, the court may consider evidence, oral or written, whether or not it is in conformity with the Evidence Code.