Building a Drone Evidence Chain of Custody Log in a Spreadsheet
A drone can capture valuable evidence during a bushfire, missing-person search, traffic investigation or crime-scene assessment. However, footage is only useful in court or an internal review when an agency can demonstrate where it came from, who handled it, what changed, and how it was protected.
A spreadsheet can provide a practical starting point for documenting that history. It should work alongside approved evidence-management software, secure storage and agency policy, rather than replacing them. The goal is a consistent, searchable record that links each drone flight and media file to a defensible chain of custody.
| Evidence stage | Spreadsheet fields | Main control |
|---|---|---|
| Capture | Flight ID, date, time, operator, aircraft, mission purpose | Record details immediately after landing |
| Transfer | Source device, transfer time, recipient, storage location | Use an authorised copy process |
| Verification | File name, size, format, hash value | Compare hashes after each approved transfer |
| Review | Reviewer, access time, purpose, export details | Keep originals separate from working copies |
| Disclosure or disposal | Release authority, recipient, return or destruction date | Follow retention and legal requirements |
Define The Evidence Record
Create a master worksheet with one row for each original file, not merely one row for each flight. A single mission may generate visible-spectrum video, still photographs, thermal imagery, telemetry, audio, flight logs and screenshots. Give every item a unique evidence ID, such as AUS-NSW-2025-0041-VID-001, and connect it to a separate flight ID.
Useful columns include incident number, location, aircraft serial number, payload or camera, operator name and accreditation, take-off and landing times, time zone, weather conditions, purpose of collection, and whether the file is original or derived. Record the camera settings and automated functions where they may affect interpretation, including zoom, thermal palette, geotagging and object tracking.
Use controlled values wherever possible. Drop-down lists for evidence type, status, access reason and disposition reduce spelling variations and make later filtering reliable. Lock headings and formula cells, protect the workbook with role-based permissions, and keep a read-only master version.
Capture Metadata At The Source
The first entry should be made as close as possible to the point of capture. Operators can record the flight identifier in a mobile form or paper field sheet, then reconcile it with the spreadsheet when connectivity returns. This matters in regional Queensland, Western Australia and the Northern Territory, where coverage can be unreliable during remote operations.
Do not rely solely on a file name or the drone application’s cloud account. Export the original media and relevant flight logs using an approved method. Record the source SD card or controller, the person who performed the transfer, the date and time, the destination folder and the software used. If a file is converted, stabilised, clipped or enhanced, create a new derivative record rather than overwriting the original.
A useful naming pattern might include the evidence ID, file type and version, such as AUS-NSW-2025-0041-VID-001_ORIGINAL.MP4 and AUS-NSW-2025-0041-VID-001_WORKING_V02.MP4. Keep the original file extension and document any format conversion.
Add Integrity And Access Controls
A cryptographic hash, such as SHA-256, produces a digital fingerprint for a file. Enter the hash in its own column immediately after acquisition, along with the tool or application used to calculate it. When the evidence is copied to a secure server, compare the new hash with the recorded value and log the result. A mismatch should trigger quarantine and investigation, not silent replacement.
The access worksheet should record who opened, copied, exported, annotated or disclosed an item, with a timestamp, purpose and authorisation reference. Use Australia’s date and time conventions consistently, and state whether the time is local, Australian Eastern Standard Time or daylight saving time. This avoids confusion when Sydney and Melbourne operations move to daylight saving while Queensland does not.
Sensitive imagery requires particular care. A drone file might reveal a person’s face, home, vehicle, medical emergency or movements. Agencies should align the spreadsheet with privacy impact assessments, applicable state or territory surveillance laws, and the federal Privacy Act 1988 where it applies. A health privacy resource can help teams think through the risks of retaining identifiable health-related imagery, although agency legal advice must govern operational decisions.
Match The Log To Australian Rules
Flight records should identify the operator’s authorisation, aircraft registration or serial details where relevant, operating area and any restrictions considered before launch. Public safety crews must account for CASA requirements under the Part 101 framework, including operating limitations, approvals, airspace conditions and the responsibilities attached to the mission. The log should point to the relevant approval or risk assessment rather than simply stating “approved.”
State and territory requirements may impose additional controls on surveillance, recording and disclosure. A mission in Sydney may involve different police, council or emergency-management arrangements from one in Melbourne, Brisbane or Perth. Agencies should document the legal basis for collection, the incident purpose, any warrant or consent reference, and the rule authorising inter-agency sharing.
Privacy and transparency should be built into procurement and policy work. Resources on drone privacy legislation can help Australian agencies compare approaches to model safeguards, public notice, retention and oversight, while local legal review remains essential.
Preserve, Audit And Review
Store the spreadsheet and media in an approved evidence repository with backups, access controls and retention schedules. Do not treat a USB drive, a personal laptop or an ordinary consumer cloud account as the permanent evidence store. If an agency uses Microsoft Excel or Google Sheets for operational convenience, export a locked PDF or spreadsheet snapshot at defined milestones and preserve the system audit history.
At the end of each shift, a supervisor should check that every flight has a mission record, every file has an evidence ID, hashes are present for originals, and transfers have named custodians. Monthly sampling can identify missing timestamps, duplicate IDs, unexplained edits or files that lack a legal-basis reference. Record corrections as new entries with the reason, author and date; never erase the original history.
A clear disposition field should show whether the item is retained, disclosed, returned, archived or destroyed. Include the authority, date and approving officer. This makes the chain of custody useful long after the incident, whether evidence is requested by a prosecutor, reviewed by an oversight body, challenged in court or examined during a community transparency process.
Adopt the spreadsheet as a controlled template, test it during a realistic exercise and train pilots, evidence officers, investigators and supervisors to use the same terms. Start with one operational team, audit the records after several missions, and then integrate the lessons into the agency’s drone program, privacy policy and evidence-management system.