Soils forensic fingerprinting

Methods of Characterizing and Fingerprinting Soils for Forensic Application... 

The use of a direct combined (or polyphasic) approach can create highly specific soil fingerprints from normal constituents. This, in addition to the application of appropriate statistical analysis, would make soil analysis a more effective tool for routine forensic work, thus considerably extending its applicability. Indeed, combinations of different data each with its own discriminatory potential may result in probabilities of association or disassociation that even surpass those of techniques such as human DNA. Initial work using a canonical variate analysis has shown discrimination between soil types can be improved by including more analytical data. Figure 11.11 illustrates... 

The larger number of points of identification that are determined, the more certain becomes the conclusion regarding the identification of questioned inks. Such forensic scientific philosophy is true not only of ink comparison but of other types of physical evidence such as soil, paint, hair, bullets and fingerprints. ... 

Forensic samples are often very small and inhomogeneous. As discussed later, it is difficult to perform quantitative analysis on such samples. However, it is possible to use qualitative XRF to good advantage. Using the spectral fingerprint of a sample does not require exact concentrations to be determined. By proving that a spectrum of soil found in a shoe matches the spectrum of soil from the location of a crime scene, it is possible to place the object at that scene. 

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