title: Forensic Comparison of Soil Samples Using Nondestructive Elemental Analysis.
abstract: Soil can play an important role in forensic cases in linking suspects or objects to a crime scene by comparing samples from the crime scene with samples derived from items. This study uses an adapted ED-XRF analysis (sieving instead of grinding to prevent destruction of microfossils) to produce elemental composition data of 20 elements. Different data processing techniques and statistical distances were evaluated using data from 50 samples and the log-LR cost (Cllr). The best performing combination, Canberra distance, relative data, and square root values, is used to construct a discriminative model. Examples of the spatial resolution of the method in crime scenes are shown for three locations, and sampling strategy is discussed. Twelve test cases were analyzed, and results showed that the method is applicable. The study shows how the combination of an analysis technique, a database, and a discriminative model can be used to compare multiple soil samples quickly.
authors.affiliation: Netherlands Forensic Institute, Laan van Ypenburg 6, 2497 GB, The Hague, The Netherlands.
authors.forename: Stefan
authors.initials: S
authors.lastname: Uitdehaag
authors.affiliation: Netherlands Forensic Institute, Laan van Ypenburg 6, 2497 GB, The Hague, The Netherlands.
authors.forename: Wim
authors.initials: W
authors.lastname: Wiarda
authors.affiliation: Department of Physical Geography, Utrecht University, Heidelberglaan 2, 3584 CS, Utrecht, The Netherlands.
authors.forename: Timme
authors.initials: T
authors.lastname: Donders
authors.affiliation: Netherlands Forensic Institute, Laan van Ypenburg 6, 2497 GB, The Hague, The Netherlands.
authors.forename: Irene
authors.initials: I
authors.lastname: Kuiper
keywords: Canberra distance; elemental composition; energy-dispersive X-ray fluorescence; forensic science; soil comparison; trace evidence