Geomorphological and geoforensic interpretation of maps, aerial imagery, conditions of diggability and the colour-coded RAG prioritization system in searches for criminal burials

Abstract

Abstract The objective of this paper is to draw attention to the use of air photographs, diggability surveys and the RAG (Red–Amber–Green) prioritization system during police ground searches for burials. The acquisition, analysis and interpretation of aerial imagery by a geologist may provide a useful reconnaissance technique to help delineate and prioritize search areas. A diggability survey may provide information on the ease and efficiency with which the ground may be dug and reinstated by an offender. This is influenced by the depth of the soils, the geology, groundwater, obstructions, the digging implements used, the ability of the offender, the nature of item being buried and the time frames involved. The results of a diggability survey may conveniently be presented as a RAG, map which can help in prioritizing the search. The RAG system appears to have been used independently by geologists, police/law enforcement and the military, and has evolved differently and independently since the early part of the 1900s. These methods have been applied to law enforcement searches for graves and other buried objects as demonstrated by operational case examples.