The Child Protective Service Unit shall determine, within 60 days, whether the report is “indicated” or “unfounded” and report it forthwith to the central register; where it is not possible to initiate or complete an investigation within 60 days the report may be deemed “undetermined” provided every effort has been made to undertake a complete investigation. The Department may extend the period in which such determinations must be made in individual cases for additional periods of up to 30 days each for good cause shown. The Department shall by rule establish what shall constitute good cause.
     In those cases in which the Child Protective Service Unit has made a final determination that a report is “indicated” or “unfounded”, the Department shall provide written notification of the final determination to the subjects of the report and to the alleged perpetrator, parents, personal guardian or legal guardian of the alleged child victim, and other persons required to receive notice by regular U.S. mail. Subject to appropriation, written notification of the final determination shall be sent to a perpetrator indicated for child abuse or child neglect, or both, by both regular and certified mail.