Forensic Geology in the Urban Environment: An Assessment of Material Transfer Behavior

Abstract

Soils and related anthropogenic materials are encountered as evidence in criminal investigations. The aim of this study was to better our understanding of soil transfer behavior in an urban environment, and to evaluate the effects of sampling and material transfer on the outcomes of forensic analyses. The underlying question was whether there is a preferential transfer of urban soil material to shoes according to the tread gap distribution. During the course of this work, control soil samples from the District of Columbia were characterized and compared with soil material that had been transferred to shoes with different tread gap distributions. Soil color, particle size distribution, and mineralogy were all discriminatory among the locations in this study. Results suggest that soil color and particle size distribution are significantly influenced by the transfer process, and further study is needed to analyze the effect of single influencing factors on the resultant material.