Locating Buried Remains Using Ground Penetrating Radar In Contrasting Soil Types.

Ground penetrating radar (GPR) is a non-invasive, geophysical tool used for the detection of clandestine graves. GPR operates by detecting density differences in soil by the transmission of high frequency electromagnetic (EM) waves from an antenna. A 500 Megahertz (MHz) centre frequency antenna is typically used for forensic investigations, as it provides a suitable compromise between depth of penetration and sub-surface resolution. Domestic pig (Sus scrofa) carcasses were clothed in 100% cotton t-shirts and 50% cotton/50% polyester briefs, and buried at a consistent depth at three field sites of contrasting soil type (silty clay loam, fine sand and fine sandy loam) in southern Ontario. GPR was used to detect and monitor the graves for a period of fourteen months post burial. Analysis of collected data revealed that GPR had applicability to detect clandestine graves containing remains in silty clay loam and fine sandy loam soils, but was not suitable for detection in fine sand soil. The results of this study will be presented, and the accuracy with which GPR can be used in the field by police agencies will be discussed.  

Key Words: forensic science, ground penetrating radar, soil type, buried remains