Desk-Based Assessment
Definition
The pre-fieldwork intelligence phase in which investigators review maps, aerial images, witness accounts, and land records to define a search area and assign initial probability to sub-zones.
- Field
- Search strategy and planning
- Timing
- Before fieldwork begins
- Inputs
- Maps, aerial imagery, witness accounts, land records
- Output
- A defined search area with probability weighting by sub-zone
Common questions
What decisions does a desk-based assessment feed into once fieldwork starts?+
It sets the boundaries of the search area and ranks sub-zones by likelihood, which drives resource allocation, such as where to deploy cadaver dogs or ground-penetrating radar first, so teams search the highest-probability ground before expanding outward.
How reliable is a desk-based assessment on its own?+
It is a planning tool, not a location finding: it narrows where to look based on indirect evidence like terrain and witness statements, but it does not confirm a burial or deposition site, which still requires physical search methods to verify.
Related terms
- Hypothesis-Led Search
- A search approach that targets specific locations predicted by intelligence or terrain analysis, testing those predictions before expanding to lower-probability areas.
- POLSA
- Police Search Advisor: a specialist role in England and Wales responsible for planning and commanding a search operation, selecting methods, and maintaining...
- Probability Mapping
- A spatial analysis technique that assigns relative likelihood scores to grid cells or terrain zones based on accessibility, soil type, offender behaviour...
- Systematic-Grid Search
- An approach that divides the search area into a uniform grid and covers each cell at equal density, used when the deposit...
- Tasking Log
- The written record of every instruction, decision, and team action during a search operation. It is a contemporaneous document admissible as evidence...