Systematic-Grid Search
Definition
An approach that divides the search area into a uniform grid and covers each cell at equal density, used when the deposit location is genuinely unknown or when completeness is required.
- Method
- Uniform grid dividing the search area into equal cells
- Coverage
- Equal search density per cell
- Best suited to
- Unknown deposit location or when completeness is required
- Domain
- Search strategy and scene/area search planning
Common questions
When would an investigator choose a systematic-grid search over a targeted or probability-based search?+
A grid search is chosen when there is no reliable prior information narrowing where evidence might be, or when the investigation legally or procedurally requires proof that the entire area was searched with equal thoroughness, rather than concentrating effort where evidence is merely most likely.
What is the main trade-off of using a grid search compared to a targeted search strategy?+
Grid search trades speed for completeness; because every cell receives equal attention regardless of likelihood, it takes longer and uses more resources than a targeted search that concentrates effort on high-probability areas identified from witness accounts, terrain, or offender behaviour.
Does cell size in a grid search affect the reliability of a negative result?+
Yes; cell size must be matched to the size of the item being sought and the search method used within each cell, since cells too large relative to the target item can let evidence go undetected even though the area was nominally covered.
Related terms
- Desk-Based Assessment
- The pre-fieldwork intelligence phase in which investigators review maps, aerial images, witness accounts, and land records to define a search area and...
- 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...
- Tasking Log
- The written record of every instruction, decision, and team action during a search operation. It is a contemporaneous document admissible as evidence...