ALPR, Drone, and Surveillance Media Retention and Privacy

Introduction

Automated License Plate Readers (ALPR), drones, and other surveillance systems have become essential tools in public safety and law enforcement. They generate massive amounts of Criminal Justice Information (CJI) and personally identifiable information (PII), requiring careful management in archives. Agencies must ensure retention schedules align with CJIS Security Policy while protecting privacy rights and maintaining evidentiary integrity. This blog explores best practices for managing ALPR, drone, and surveillance media.

Key Challenges

1. High Data Volumes: Continuous ALPR and drone feeds produce petabytes of data.
2. Privacy Risks: Data often captures non-target individuals and vehicles.
3. Retention Complexity: Different mandates apply to investigatory vs. incidental captures.
4. Legal Defensibility: Improper handling can undermine admissibility in court.

Retention Considerations

• ALPR Data: Retention policies vary by jurisdiction (30 days to multiple years). Non-hit records (no investigative value) are typically subject to shorter retention.
• Drone Media: Retain based on case relevance. Routine patrol footage may have shorter schedules, while evidence-related captures require long-term preservation.
• Surveillance Media: Apply retention aligned with state/local mandates and privacy requirements.

Best Practices:

• Define tiered retention schedules distinguishing investigatory vs. incidental data.
• Automate defensible deletion of non-relevant captures.
• Document retention policies and map them to CJIS controls.

Privacy Safeguards

• Minimization: Capture only what is necessary for operational or investigative purposes.
• Redaction/Blurring: Apply redaction to protect bystanders’ identities in non-relevant footage.
• Access Controls: Limit access to surveillance archives with MFA and RBAC.
• Transparency: Publish retention policies where required to maintain public trust.

Evidentiary Integrity

• Store relevant footage in WORM or immutable storage to prevent alteration.
• Use cryptographic hashing to validate file integrity.
• Maintain audit trails documenting all access, exports, and deletions.

Mapping to CJIS Security Policy

• Access Control: Ensure only authorized personnel access surveillance archives.
• Audit & Accountability: Maintain detailed logs for retention, deletion, and evidence access.
• Cryptographic Controls: Use FIPS-validated encryption for storage and transmission.
• Privacy Protections: Apply minimization and redaction to align with privacy principles.

Conclusion

Managing ALPR, drone, and surveillance media requires balancing evidentiary needs with privacy and compliance. By applying tiered retention schedules, minimization practices, and immutable storage, agencies can ensure that surveillance archives remain defensible, compliant, and respectful of civil liberties while supporting public safety operations.