Geoforensics and Information Management for crime Investigation (GIMI)
New Technologies
The principal technologies involved focus upon non-invasive detection and measurement of sub-surface features, geographical modelling of areas of search and the communication and interpretation of observations.
The employment of ground based radar (GBR) to assist police and law enforcement investigation teams in forensic searches can enable large areas to be searched quickly and non-destructively for buried objects, hides and caches, and the detection of cavities both in the ground and in structures. This greatly improves search efficiency and reduces unnecessary excavation operations.
Linking descriptions of soil characteristics from analytical and non-invasive sources with existing Geographic Information Systems (GIS) and associated databases of soils and vegetation enables areas of search to be geographically targeted. For example, sites can be identified by a combination of soil and vegetation characteristics derived from analysis of evidence. Other geographic datasets (e.g. data on transport routes and population centres) can then be used in combination with those of soils and vegetation to explore hypotheses regarding worthwhile areas of search.
Linking the non-invasive measurment techniques with those of geographic description and modelling offers the potential for matching the properties of sites from case evidence with geographic databases, thereby identifying possible target areas for searching.
Other geophysical methods also have a role in forensic investigations. Very accurate magnetic surveys can detect areas of soil disturbance since in-situ soil horizons very often have variations in magnetic susceptibility. Ground electrical conductivity surveys are a very rapid means of obtaining the distribution of electrical conductivity in the near surface that might be related to altered moisture profiles as a result of soil disturbance. A more accurate distribution of ground electrical conductivity can be obtained with electrical imaging techniques. Such techniques employ sensors mounted on wheeled trolleys, vehicles and aircraft. Visualization underneath buildings is also possible.