Experimental forensic scenes for the characterization of ground-penetrating radar wave response

Abstract

Over the last few decades, the use of non-intrusive geophysical techniques, which allows for coverage of an entire crime scene in a reasonable amount of time, in forensic investigation has increased. In this study, we analyze the effectiveness of ground-penetrating radar (GPR) in forensics. Experimental scenes were simulated and some of the most commonly buried items in actual crime scenes were introduced, such as bone remains, guns and drug caches. Later, a GPR survey was conducted on the experimental grids with a 500 MHz antenna. The final purpose was to characterize the radar wave response expected for each set of remains to assist with its identification in later actual investigations. The results collected provided promising information that can be used when surveying real cases. Nevertheless, there were some interpretational difficulties regarding the sizes of the items and the electromagnetic properties of the materials. For these cases, finite-difference time-domain modeling was employed to achieve an advanced interpretation of the field data. The simulated models used were built from accurate geometric data provided by photogrammetric methods, which replicate the experimental scenes in fine detail. Furthermore, this approach allowed for the simulation of more realistic models, and the synthetic data obtained provided valuable information for assisting in the interpretation of field data. As a result of this work, it was concluded that GPR can be an effective tool when searching for a variety of materials during a crime scene investigation.