Editorial

Abstract

Welcome to this special edition of X-ray spectrometry in forensics! The X-ray spectrometry technique scanning electron microscope energy dispersive X-ray analysis (SEM-EDS) is widely used by forensic laboratories for the examination of trace evidence. The technique is used in the international standard for gunshot residue analysis and is also used for the analysis of fibres, hair, glass and paint specimens, to name a few. The technique has gained increasing popularity since the 1970s because of its low cost, non destructive nature, ease of operation and interpretation. In this edition, we will see how complementary X-ray spectrometry methods may assist the forensic investigations of the future. In particular, Galli et al. show how portable X-ray fluorescence (XRF) devices are used in the related field of cultural heritage and how some of the advantages of portable XRF might be translated to forensic samples. On this theme, Fonseca et al. will show how XRF can be used to estimate shooting distance, and Ernst et al. outline a protocol for forensic glass analysis by using XRF. On a larger scale to tube XRF, synchrotron XRF (SXRF) has been recently used in a murder case in Japan, and Kawai gives an interesting account of the Jury's interpretation of the SXRF data from two experts, adding his own interpretation to the data, highlighting the complexity of interpretation of XRS spectra in a forensic context. Nakai et al. will show how a soil database is being constructed in Japan by using SXRF, outlining a new and useful application of the technique in forensic science. As SEM-EDS is a noteworthy force in forensics, optimisation and modification of the technique are essential to meet increasing demands from police organisations for high throughput, low cost and robust analytical techniques. Levin et al. meet these demands in the context of high throughput gunshot residue analysis by capitalising on new developments in instrumentation. Their article provides a guide, which will be useful for other forensic laboratories interested in installing silicon drift detectors. In complement to this article, French et al. use SEM-EDS to look at the possibility of secondary transfer of gunshot residue under various circumstances, putting the spotlight on the interpretation of gunshot residue evidence in the courts. It is evident from this edition that X-ray spectrometry techniques have a great range of potential and exciting new applications, which could have a significant impact on police investigations.