Soils in forensic science: Underground meets underworld

Abstract

Security and environmental health issues are high on international political and social agendas, with public policy leading to legislation on environmental liability, and support for improved technologies and capabilities for use by relevant authorities. The role of soils and geological material, and their associated ecological properties, as significant sources of intelligence and physical evidence is increasingly recognised by those involved in criminal investigations. The transference of soil, or objects held within the soil matrix, has enabled associations between combinations of victim or artefact, perpetrator, and locations; demonstrable to a standard of proof and transparency required to substantiate evidence in courts of law. Formalisation of approaches to areas of search, site identification, measurement and excavation has provided a framework for structuring strategic and tactical planning of investigations. Greater attention is now being paid to new means of data capture and its interpretation, including the production of robust databases of the properties and spatial distribution of soils and underlying geological influences. Public investment is being made in research, development and operational use by investigating authorities of a toolbox of soil forensic techniques. These include isotopic analysis, non-invasive means of measurement and mapping, and the identification of properties using biological, pedological, sedimentological and geographical approaches. The advantages of integration and appropriate coupling of complementary and independent measures is now being recognised. Some tools are at a conceptual stage, such as contingency planning for mass graves, and others experimental, such as novel taggants. Others are subject to testing in different environmental conditions to assess their capacity to discriminate between contrasting anthropogenic influences. Yet, in countries such as Australia, the UK, and the USA the analysis of soils is being used successfully in legal submissions on issues from site verification to body decomposition. Although some statistical principles are becoming incorporated into forensic soil science there is a need for further development in this area, and greater dialogue between statisticians, environmental scientists, forensic scientists and practitioners. However, the co-authorship of the chapters in this book, across a wide range of disciplines and levels of practice, demonstrates the significance of developing close working relations and understanding for greatest societal benefit to be gained from the work on soil forensics, both in a criminal and an environmental context. The challenges are to identify and address interdisciplinary research questions, and to advance and prove technological developments such that they appropriately support intelligence gathering and the provision of reliable evidence. The maturing disciplines of criminal and environmental soil forensics will then deliver on the expectations and demands of public policy around the world.