Log each report the moment you know of the apparent violation, then mark it reported with NCMEC's report number. From the day it was reported, what was reported is held for one year; a law-enforcement request or your own decision can hold it longer, never shorter. Tipstaff never holds the material, a thumbnail or a description of it - only where your secure store keeps it, and dates.
The law asks that preserved material sit in a secure place and that access be limited to what compliance needs. Every opening is written here before it happens, by a person on your staff list, with the reason. Nothing in this log can be changed or taken out.
Reports whose hold has ended and whose preserved material was let go: when it was reported, the hold that applied, and who released it and why.