Evidence Media Processing

Overview#

A homicide investigation generates hours of body camera footage, dozens of CCTV clips in proprietary formats, and hundreds of photographs from the scene. Detectives need to review that material quickly. Prosecutors need to play it in court without format compatibility issues. Forensic analysts need to extract audio tracks, isolate frames, and search for specific objects across the full collection. Processing all of that manually, file by file, takes time that active investigations rarely have.

The Evidence Media Processing module transforms raw multimedia evidence into searchable, reviewable, and court-presentable formats through automated processing pipelines. Video is transcoded to playback-compatible formats. Audio is extracted and transcribed. Images are analysed by AI for object detection, face recognition readiness, and content classification. Throughout every transformation, the original file is preserved unchanged and the chain of custody is maintained for each derivative output. The module meets the forensic integrity standards required by criminal courts, digital forensics labs, and prosecutorial offices.

Key Features#

• Video transcoding to multiple playback-compatible formats, with quality optimisation for court presentation and field access
• Audio extraction and analysis from video evidence, producing separate audio tracks and searchable transcripts
• AI-powered image analysis for object detection, content classification, and metadata extraction from evidence photographs
• Automated metadata extraction from multimedia files, capturing device information, timestamps, and geolocation where available
• Forensic integrity preservation throughout all processing: the original file is never modified, and every derivative is linked to the master with a hash-verified provenance record
• Chain of custody compliance for all media transformations, with each processing step logged with actor identity and timestamp
• Searchable format generation enabling full-text and content-based search across all processed evidence types
• Batch processing for large multimedia evidence collections, with parallel pipelines to keep throughput high

Use Cases#

• Transcoding body camera and surveillance video from proprietary formats for efficient review, courtroom playback, and disclosure to defence teams
• Extracting and transcribing audio content from video evidence to support keyword searches and statement analysis
• Running AI-powered image analysis on scene photographs and surveillance stills for object and content detection
• Processing large multimedia evidence collections from major seizures while maintaining forensic integrity throughout

Integration#

The Evidence Media Processing module connects with evidence management, chain of custody, and AI analysis services for end-to-end multimedia evidence workflows.

Open Standards#

• SHA-256 (FIPS PUB 180-4): Every evidence file ingested into the pipeline is hashed with SHA-256; the digest is recorded on the evidence record and repeated in each chain-of-custody entry to verify end-to-end integrity.
• AES-256-GCM (FIPS PUB 197 / NIST SP 800-38D): Master evidence files are stored at rest using AES-256-GCM authenticated encryption, with the algorithm recorded per evidence item.
• RFC 3161, Internet X.509 PKI Time-Stamp Protocol: Evidence export packages support optional RFC 3161 trusted-timestamp tokens, embedding a third-party-verifiable timestamp alongside the file hash to meet court admissibility requirements.
• W3C Verifiable Credentials Data Model v2.0: Signed provenance credentials are issued for each evidence item and custody transfer using did:web decentralised identifiers and Ed25519Signature2020, providing cryptographically verifiable chain-of-custody records.
• IANA Media Types / MIME (RFC 2046): Every file submitted to the processing pipeline is classified by its MIME type, which drives routing decisions across OCR, transcoding, and AI analysis stages.
• RFC 2822, Internet Message Format: Email evidence files in .eml format are parsed against RFC 2822 header fields (From, To, Message-ID, In-Reply-To, References) to reconstruct message threads and extract attachments.
• ISO/IEC 14496-14 (MP4) and IETF WebM with VP9: Video clips extracted from surveillance recordings are stored as ISO Base Media File Format (MP4, H.265 codec) containers; preview derivatives are transcoded to WebM using the VP9 codec via ffmpeg.
• EXIF (CIPA DC-008 / ISO 12234-2): Embedded EXIF metadata is extracted from image and video evidence at ingest, capturing device identifiers, capture timestamps, and GPS geolocation where present.

Last Reviewed: 2026-02-23 Last Updated: 2026-04-14