Soil Comparisons Using Small Soil Traces, A Case Report

Abstract

In forensic investigations, soil traces from pieces of evidence (e.g. shoes, shovels) can be compared to each other or to soil samples from the crime scene. A case report is presented on an attempted rape case using bacterial terminal restriction fragment length polymorphism (tRFLP) profiling and pollen analysis. From both the victim’s and the suspect’s clothing soil stains were sampled. No samples from the crime scene were supplied. For both the bacterial profiles and the pollen spectra of the soil samples Bray-Curtis distances were calculated and interpreted using databases. For the pollen spectra palynological knowledge on the frequency of the pollen types was also taken into account. The Bayesian approach was used to express the evidential value of the combined results in which multiple common characteristics were used as opposed to only rare characteristics.