The use of grain size distribution analysis of sediments and soils in forensic enquiry

The use of grain size distribution analysis in forensic enquiry was investigated with reference to four forensic case studies which contained the type of sample restraints and limitations often encountered in criminal case work. The problems of the comparison of trace and bulk samples are outlined and the need for multiple sample analysis is highlighted. It was found that the problems of soil analysis, particularly when the soil was recovered from anthropogenic sources, focused on the lack of identification of pre-, syn- and post-forensic event mixing of materials, thus obscuring the recognition of false-negative or false-positive exclusions between samples. It was found that grain size distribution analysis was a useful descriptive tool but it was concluded that if it were to be used in any other manner the derived results should be treated with great caution. The statistical analyses of these data did not improve the quality of the interpretation of the results.