Mark Neale Harrison

Locating Concealed Homicide Victims: Developing the Role of Geoforensics

Historically police searches for homicide victims’ graves have been undertaken by the use of large numbers of police, military and public volunteers, conducting visual or manual probe line searches covering formalised gridded sectored areas. Speculative digging of large areas of ground has also been employed with variable success. Mineral exploration geologists, engineering geologists and geohazards specialists traditionally investigate the ground using a range of methods and techniques. Before such ground investigations are undertaken, a conceptual geological model of the ground is developed. This provides information on, for example: tectonic setting, stratigraphy, lithology, structure, hydrogeology, hydrology, groundwater, hydrochemistry, superficial deposits, principal soil types, depth to bedrock, nature of bedrock interface, engineering and physical properties of the ground, geomorphological processes, mining, past land use, current land use, geological hazards and man’s influences. In a similar way, the properties of a buried or concealed body may also be determined and how in particular these have influenced the geology. This provides estimates of the target’s age, size, and geometry, expected depth of burial, time and duration of burial, state of preservation or decomposition, physical, chemical, hydrogeological and geotechnical variations compared to the surrounding ground. An understating of the undisturbed (pre-burial) and disturbed (post-burial) geology and the target (body and associated objects) properties are crucial before the correct search strategy and choice of instrumentation may be decided, and the optimum method of deployment identified. These may include M. Harrison National Policing Improvement Agency, Wyboston Lakes, Great North Road, Wyboston, Bedfordshire MK443AL and School of Ocean and Earth Science, University of Southampton, Waterfront Campus, European Way, Southampton SO14 3ZH, UK L.J. Donnelly(*ü ) Halcrow Group Ltd., Deanway Technology Centre, Wilmslow Road, Handforth, Cheshire, SK9 3FB, UK e-mail: DonnellyLJ@Halcrow.com K. Ritz et al. (eds.), Criminal and Environmental Soil Forensics 197