EGS - Soil in criminal investigations: investigation and evaluation in current and cold cases
Prof Lorna Dawson, James Hutton Institute
Forensic soil science is an increasingly important discipline involving soils, minerals, dusts, plants and rock fragments to determine provenance i.e. to provide a chronology of their ownership, custody or location and as a comparison with a crime scene. Soil materials have been used as forensic trace evidence from early Roman times, and are often highly distinctive from one region to another . Such traces are extremely useful in a forensic context, because of their environmental specificity; their high levels of transferability; their ability to persist on items such as clothing, footwear, tools and vehicles; and their high levels of preservation after long periods of time. This resilience makes soil trace materials, often present at crime scenes and on forensic exhibits, highly valuable forms of intelligence and evidence that can aid crime investigations and scenario reconstructions. Significant advances in forensic geoscience over the past decade, in the development of analytical approaches, miniaturisation and also in understanding the behaviour, transfer, persistence and preservation of sediments, soils and plant material have widened their applicability and evidential value. Evidence samples can be analysed using a wide range of complementary methods that address their physical, chemical and biological components with greater precision, speed and accuracy than ever before. This now permits samples of less than 10 milligrams to be accurately characterised, and permits forensic soil science to also contribute to cold case investigations, both in providing intelligence and evidence in court. Examples will be presented of case work where soil has played a pivotal role.
Sediments/soil on footwear and vehicles can indicate where a crime may have taken place, and may provide evidence of a person being at a particular place of interest. Improved analytical capabilities, coupled with the development and availability of relevant databases, allow forensic geoscientists to help police to search for unknown objects or people, prioritise areas for investigation or search, and provide robust and reliable evidence in court. Forensic geoscience has mainly been used in the past in the context of high-impact crimes such as murder, rape, aggravated burglary and terrorism investigations, where resources allow it. However, techniques are becoming cheaper and faster, and have the potential to become regularly used. With developments in analytical technology, and an increasing understanding of how soils and sediments are distributed within natural and anthropogenic environments, forensic soil science has more power to answer questions such as: “Where did the soil material come from?’, or “Where has this item been?”. Understanding the context of a specific case is crucial to help answer such questions. In addition, being able to explain the significance of the evidence that has been analysed, and demonstrating logically and transparently how a conclusion has been reached, remains important for forensic soil science specifically and trace evidence generally.
 Dawson, L.A., Mayes, R.W., 2015. Criminal and Environmental Soil Forensics. In: Murphy, B.L., Morrison, R.D. (Eds.), Introduction to Environmental Forensics, pp. 457–486.
Professor Lorna Dawson, BSc (Hons) (Geography, Edinburgh University), PhD (Soil Science, Aberdeen University), is head of Forensic Soil Science at the James Hutton Institute, visiting professor of Forensic Science at Robert Gordon University, a Chartered Scientist, a Fellow of the Institute of British Soil Scientists, and a Fellow of the Royal Society of Arts. She is a registered expert with the National Crime Agency, works with police forces and agencies across the UK and overseas soil trace evidence provision in search and evidence and has written over 100 forensic reports.
She holds diplomas in civil and criminal law (Cardiff University, 2011, 2012 and a Masterclass in Expert Witness Report writing, 2017) and regularly attends court as an expert witness. She sits on the British Association of Science General Committee, holds a diploma in Science Communication from Bristol University (2010) and is the Knowledge Exchange Lead for Environment for the Scottish Government SEFARI Gateway. She is treasurer of the IUGS-IFG (International Union of Geological Sciences-Initiative on Forensic Geology) and regularly takes part in training police and forensic practitioners world wide. She is an advisor to the CBRN-GIFT (Generic Integrated Forensic Toolbox to investigate Chemical, Biological, RadioNuclear incidents), and is a member of the ASPT (Animals, Soil, Plant Trace) working group of two the ENFSI (European Network of Forensic Science Institutes). Lorna is a member of the European COST action 16101 Multi Forensee, representing multi spectral imaging of soil for forensic use. She has acted as an expert on many high profile cases such as the search for Ben Needham, Pamela Jackson, Moira Anderson and has given evidence in many cases including R v Blakey, R v Halliwell, WA v Rayney, HMA v Pacteau, and HMA v Sinclair.
Organised by :
Edinburgh Geological Society