Evidence chain of custody basics for techs

Overview

Chain-of-custody documentation shows that digital and physical evidence was not altered between collection and analysis. Field technicians are often the first link—train them on a short, repeatable standard.

Record fields

Document who collected evidence, when, where the device was located, what actions were taken (photographs, powered-off state, forensic image), packaging identifiers, and seal numbers if used.

Physical handling

Prefer write blockers for disk imaging, anti-static packaging, and photographs of serial numbers before removing equipment from the rack when safe to do so.

Transfers

Obtain dated signatures from both the person releasing and receiving evidence. “I will sign later” breaks the chain.

Digital exports

Compute and store SHA-256 hashes separately from image files; for cloud exports, keep JSON manifests listing object keys and checksums.

Common failures

Reimaging before photographs exist; posting sensitive screen captures to public chat channels; shipping drives without tracking on high-sensitivity matters.

Storage

Locked cabinets with explicit ACLs; encrypted removable media at rest.

Drills

Run a quarterly evidence drill and time how long a junior tech takes to complete paperwork correctly without panic support.