Chain of custody is the documented history of how a recording was handled. Your workflow should make it possible to explain where the media came from, who had access to it, what processing occurred, and which file is the preserved original.
Begin at acquisition. Use clearly identified media, confirm that cards are ready before the assignment, and do not delete or overwrite recordings in the field. At the end of the session, note the matter, date, media identifier, and operator responsible for the transfer.
Create a verified copy to controlled storage. Preserve the camera-original files, use checksums when your workflow supports them, and keep working exports separate from the originals. Renaming an export may be useful; altering the only source file is not.
Every handoff should be intentional. Record the recipient, method, date, and the exact files delivered. Use secure transfer systems, apply access controls, and avoid consumer sharing links that expose confidential material beyond the intended parties.
Retention and deletion should follow the engagement terms and applicable requirements. When the retention period ends, document the authorized disposition. Consistent records turn good technical practice into a defensible professional process.