X-ray diffraction (XRD) evaluation of questioned cremains.

The practice of cremating human remains is becoming increasingly common around the world, which has also resulted in increased incidents of mishandling, illegal disposal, and fraud. X-ray diffraction (XRD) offers a clear method of differentiating cremated remains from common filler materials, such as cement and wood ash. XRD can also be used to determine if cremated remains have been contaminated, and if so, to what extent. An evaluation of published data and in-house work, however, demonstrates that XRD cannot be used to differentiate human cremains from the processed cremains of other animals. XRD is a powerful analytical technique but must be employed with an understanding of both the limits of the instrumentation and the wide diversity of the human population.

The use of portable XRF as a forensic geoscience non-destructive trace evidence tool for environmental and criminal investigations.

Hand-held, portable X-Ray fluorescence instruments (pXRF) provide a means of rapid, in-situ chemical characterisation that has considerable application as a rapid trace evidence characterisation tool in forensic geoscience. This study presents both a control test study which demonstrates optimisation of the data collection process, alongside a range of individual forensic case studies, including heavy metal contamination, conflict archaeology, forensic soil characterisation, and verification of human remains, which together validate the technique and provide some comparison between field-based and laboratory-based pXRF applications. Results highlight the time-efficiency and cost-effectiveness of in-situ, field-based pXRF analyses for material characterisation when compared with other trace evidence methods. Analytical precision of various analytes during in-situ analysis was sufficient to demonstrate considerable application of field-based pXRF as a tool for rapid identification of specific areas of interest to be further investigated. Laboratory-based pXRF analyses yielded greater accuracy which could provide an efficient compromise between field-based pXRF and traditional laboratory-based analytical techniques (e.g. WD-XRF, ICP-MS). Further studies should collect more advanced datasets in more diverse locations to further validate the techniques capability to rapidly conduct geochemical surveys in a range of environments.