Witness Mark
Definition
A fragment embedded in a structural surface (wall, column, vehicle panel) at a known position and angle, providing a directional vector back toward the seat of blast and a velocity constraint on the fragment at impact.
Related terms
- Crater Glass
- Glass fragments recovered from within or immediately adjacent to the blast crater, originating from the device container or adjacent glazing; distinguished by...
- Expanding Concentric Search Grid
- The systematic spatial framework for post-blast scene searches, consisting of concentric rings at measured radii from the seat of blast, divided into...
- Ion Mobility Spectrometry (IMS)
- A field-deployable analytical technique that separates ions by their mobility in an electric field at atmospheric pressure. Used for trace explosive detection...
- JESIP
- Joint Emergency Services Interoperability Programme (UK); the framework mandating co-located multi-agency command with a shared decision log from initial response, applied to...
- Paint Transfer Analysis
- Forensic comparison of paint layer sequences (primer, base coat, lacquer) on near-field surfaces against reference samples to identify the vehicle or container...
- Render-Safe Procedure
- The action taken by a qualified EOD or bomb disposal team to make a blast scene or live device safe from secondary...
- Scene Log
- The contemporaneous record of every person entering and exiting the inner cordon, with time stamps and roles; the foundational chain-of-custody document for...
- Seat of Blast
- The precise point of initiation of the detonation, identified from the convergence of crater geometry, witness-mark vectors, damage gradient, and residue concentration.
- Sieve Recovery
- The process of collecting and dry- or wet-sieving soil and debris from the crater and innermost grid zone through 2 mm and...
Explained in
- Post-Blast Scene: Search Grid, Fragment Collection, Seat of BlastA fragment embedded in a structural surface (wall, column, vehicle panel) at a known position and angle, providing a directional vector back toward the seat of...