The Development of a Portuguese Database of Soils for Forensic Applications.

In the framework of the project PTDC/CTE-GEX/67442/2006 (Science and Technology Foundation, Portugal) a database of soils for forensic purposes is being developed in collaboration with the Portuguese Scientific Police. For this purpose, soil samples have been collected and analyzed by a combination of geoforensic techniques, and the following properties studied: colour (spectrophotometry), particle size distribution (laser granulometry), chemical composition (ICP-MS), low-field magnetic susceptibility (susceptibility meter), and mineralogy (optical microscopy and micro-Raman spectroscopy). The ability of these properties to allow the discrimination between samples and sites, as well as the influence of the surrounding lithology in such discrimination was investigated. It is expected that this database will be useful in the future providing soil forensic intelligence to crime investigations.