Development of soil forensic methods and databases from targeted locations in Tasmania to assist Police

Across Australia, Police rely heavily on DNA evidence and witness testimony to solve crime. Historically, this provided enough evidence to charge an offender. But in recent major crime investigations, soil evidence compared and characterised using the approach and methods outlined by CAFSS (Fitzpatrick and Raven 2012), has proved crucial in successfully assisting police and convicting offenders in Australian Courts of Law. However, most Police forensic laboratories are ill-equipped to analyse forensic soil evidence. A rising tide of unsolved ‘cold case’ major crime, with no DNA evidence or reliable witnesses, is ‘gathering dust’ on Police books. With assistance from Tasmania Police, forensic soil data from specific soil types at the following targeted locations will be gathered, to assist with new avenues of inquiry: • Key soil catenary sequences near Richmond, Hobart will be used to test distinctness of mixed pit spoil and single pit spoils via “credible scenarios of crime scene approach”. • Human-made or human-transported soils (Anthroposols) in a high-crime area of Hobart. • Organic-rich ‘peaty’soil (Organosols) from high-altitude in Tasmania. • Coastal and inland Acid Sulfate Soils from Tamar Estuary, Launceston. • Cultivated soil from commercial opium poppy plantations across Tasmania. • Use of spectrophotometry to quantify colour of a diverse range of Tasmanian soil types. Soil samples will be characterised according to the four-stage process developed by CAFSS, including detailed soil morphology characterisation of soil, mineral and organic composition using a combination of X-ray diffraction (XRD), magnetic susceptibility, heavy mineral and magnetic fractionation. Soil-regolith conceptual models and maps will complete analysis of each site. The capacity of different soil properties to discriminate between not only diverse soil types, but very similar soil samples from close geographic locations, as well as soil trace evidence, shall be investigated. Reference Fitzpatrick, R. W. and M. D. Raven. (2012). Guidelines for conducting criminal and environmental soil forensic investigations (Version 6). Report No. CAFSS_076. Australia: Centre for Australian Forensic Soil Science http://www.clw.csiro.au/cafss/. (accessed 26 April. 2012).