A California user may report material in which they, or a person they look after, can be identified. Confirm receipt in writing within 36 hours; update them every 7 days; decide within 30 days; and if it is verified, remove it and block it for good. Warden never holds the material, a still or a description - only its address, the block reference and dates. Report it to NCMEC as the law there requires; that is a separate record.
What a court would ask to see: received, confirmed, each update, the decision, removal and block, and the reporter told.
Each verified item blocked permanently, by the reference your hash-matching or upload filter uses, with the report it came from.