A local department shall complete and document an investigation using assessment tools and forms required by the Administration. A local department or, in a joint investigation, a law enforcement agency shall: To the extent possible, complete an investigation within 10 days of receiving a report; or If additional time is required, complete the investigation within 60 days of receiving a report. An investigation is complete when the local department has completed the requirements of Regulation .07A and B of this chapter and a supervisor has approved the finding.