This thesis investigates the feasibility of geochemical analysis techniques in forensic investigation, the issues associated with interpreting mixed provenance geochemical evidence and factors that could potentially influence the conclusions drawn. Two forensically relevant locations in the UK were selected for the study. Within these locations three sites were selected with differing land-use characteristics to assess the feasibility of X-ray Fluorescence Spectroscopy, Inductively Coupled Plasma-Atomic Emission Spectroscopy, Inductively Coupled Plasma-Mass Spectroscopy, Isotope Ratio Mass Spectroscopy and Quantitative Evaluation of Materials by Scanning Electron Microscopy techniques in distinguishing between geographically similar samples. The ability of these techniques to provide intelligence from material recovered from exhibits that are pertinent to a forensic investigation, e.g. footwear, was also assessed through the analysis of artificially created mixtures containing material from these sites. Sampling was conducted at quarterly intervals over a 12 month period to monitor the degree of temporal variation between samples from each
site. Additionally, differences in the plastic sample bag
packaging and storage conditions were explored to identify the optimum packaging, sample state, storage temperature and storage duration for soil/sediment material that is to undergo chemical analysis. Statistical analysis of the geochemical data revealed inter-site variation to be
significant while intra-site variation and temporal variance was non-significant at each location and no significant difference was identified between packaging material, storage conditions and storage duration. The interpretation of mixed provenance samples was far more complex and identified the potential for false negative and false positive conclusions to be drawn. This thesis presents
the first systematic empirical data set that addresses the issue of mixed and single source sample comparison by geochemical analysis, outlines a procedure for the hand
ling of geological evidence, and provides a basis upon which
to build future research that addresses the interpretation issues that have been identified
