The hearing and burden of proof.

(a) The ALJ shall conduct a hearing on the record in order to determine whether the defendant is liable for a civil penalty or assessment under § 224.3, and if so, the appropriate amount of any such civil penalty or assessment considering any aggravating or mitigating factors. (b) A.I.D. shall prove defendant's liability and any aggravating factors by a preponderance of the evidence. (c) The defendant shall prove any affirmative defenses and any mitigating factors by a preponderance of the evidence. (d) The hearing shall be open to the public unless otherwise ordered by the ALJ for good cause shown.