Overview#
A detective seizes a laptop at a crime scene. From that moment, every person who touches the device, every location it passes through, and every examination performed on it must be documented without gaps. A single missing handoff record, an undocumented overnight transfer, or a seal broken without witness notes can be enough for defence counsel to challenge admissibility. The Evidence Chain of Custody module tracks physical and digital evidence from collection through final disposition, maintaining an unbroken record that courts, prosecutors, and forensic examiners can rely on.
The module applies equally to criminal investigation units managing physical exhibits, digital forensics labs handling cloned drives, financial regulators preserving trading records, coroner services tracking biological samples, and military intelligence units managing classified material. In every context, the core requirement is the same: a tamper-evident, continuously verified account of where evidence has been, who handled it, and what condition it was in at each stage.
Key Features#
- Lifecycle Management: Tracks evidence through all phases, from collection and transfer through storage and final disposition, with complete documentation at each stage
- Custody Transfer Tracking: Records every handoff between custodians with pre-transfer integrity checks, multi-signature capture, and post-transfer fixity verification
- Evidence Sealing and Integrity Verification: Monitors seal status (intact, compromised, or broken) with photo documentation and comparison tools to detect tampering between custody events
- Access Control and Logging: Enforces role-based access and logs every access event with user identity, timestamp, action type, and duration for complete accountability
- Comprehensive Documentation: Captures collection notes, location data, condition descriptions, AES-256-GCM encrypted storage details, and disposition records for every evidence item
- Chain Integrity Assessment: Evaluates physical integrity, documentation completeness, authorisation compliance, and timeline validity to produce an overall chain strength score
- Anomaly Detection: Identifies unauthorised access attempts, after-hours activity, documentation gaps, and other irregularities that could compromise evidence admissibility
- Digital Evidence Support: Handles forensic imaging workflows with hash-based fixity verification, analyst access tracking, and derivative management for digital evidence items
- Legal Compliance Framework: Maps custody practices against federal, state, and Irish court admissibility rules, preservation requirements, and jurisdictional standards
- Real-Time Status Dashboard: Provides at-a-glance visibility into current seal status, last access, storage location, chain completeness metrics, and active compliance alerts
- Court-Ready Reporting: Generates complete chain of custody reports with visual timelines, handler lists, gap analysis, and admissibility assessments, suitable for PDF/A-3 archival export
Use Cases#
- Maintaining admissible evidence chains for criminal investigations by documenting every transfer, access event, and storage condition from collection through trial
- Ensuring compliance with evidence preservation rules and retention schedules, with automated alerts for legal holds and approaching deadlines
- Detecting chain of custody issues early through automated integrity checks and anomaly detection, allowing corrective action before admissibility is at risk
- Managing digital evidence workflows including forensic imaging, fixity verification, analyst access tracking, and expert report generation
- Supporting after-action and compliance reviews with comprehensive audit trails documenting all custody decisions, access events, and disposition actions
Integration#
The module connects with case management, evidence storage systems, and legal proceedings workflows to keep custody records synchronised with investigation activities and court requirements throughout the evidence lifecycle.
Open Standards#
- NIST FIPS 180-4 (SHA-256): Every custody event records SHA-256 digests of the evidence file bytes before and after each transfer, providing cryptographic fixity verification throughout the chain.
- RFC 8032 (Ed25519 Digital Signatures): Each chain-of-custody entry is signed with an Ed25519 private key; signatures are stored alongside the event record and verified on access to detect any tampering.
- W3C Verifiable Credentials Data Model v2.0: Evidence collection and custody transfer events are wrapped in W3C VCs, serialised as compact JWTs with a DID-based issuer, and stored to give a cryptographically provable, machine-readable provenance chain.
- RFC 3161 (Internet X.509 PKI Time-Stamp Protocol): Court-ready export packages support RFC 3161 trusted timestamp tokens embedded directly in the export artefact, anchoring evidence existence to a trusted time authority.
- ISO 19005 (PDF/A Archival Format): Chain-of-custody reports are exported as PDF/A-1B, PDF/A-2B, PDF/A-3B, or PDF/A-4F according to ISO 19005 parts 1 through 4, ensuring long-term readability and admissibility in court proceedings.
- GraphQL (June 2018 Specification): All custody queries, custody transfer mutations, and Verifiable Credential operations are exposed through a GraphQL API with role-based permission classes enforced per resolver.
- Merkle Tree Integrity (RFC 6962 pattern): Daily audit logs are committed into a Merkle tree; the stored root and inclusion proofs allow any custody record to be independently verified against the published tree root.
Last Reviewed: 2026-02-05 Last Updated: 2026-04-14