This study has provided an important first step towards understanding the transfer dynamics of diatoms as evidence in forensic geoscience investigations, and identified the methods appropriate for their collection from clothing. Diatoms can be used as circumstantial evidence in those crime scenes involving both water and soil evidence, although species richness is determined to be more distinctive within aquatic sites. Of the three methods examined, the H2O2 procedure is recommended as the most effective in yielding both the highest diatom count and most representative species richness data for comparison from clothing samples.
The findings of this research observe spatial and temporal variation in the collection of evidential samples, both control and experimental. Under experimental conditions, diatoms transfer in relatively high numbers following brief contact with aquatic sites, highlighting the potential for diatom analysis in a range of forensic contexts. Small scale spatial variability should be considered in the collection of a representative control sample for comparison. This investigation therefore concludes that multiple control and experimental clothing samples should be collected and analysed in order to account for such variability in the transfer of diatoms to recipient surfaces.
Initial empirical data have been provided in this study to support the use of diatom analysis as a valuable independent technique for the assessment of geoforensic trace evidence. This study provides an insight into the most effective methods for the collection of diatom particulates on a variety of substrates within criminal investigation. Finally, the findings contribute to the construction of an evidence base that will enable diatom evidence to be accurately interpreted and presented in a court of law.