This study determined the applicability of ground-penetrating radar (GPR) for detecting graves affected by various factors that were controlled for this research, including how the GPR was employed.
The research design included constructing a grid on secured land in a field that contained eight graves created in Spodosol, a common soil type in Florida. Six burial scenarios contained a pig carcass at a deep (1.00 m) or a shallow (.50 m) depth; a shallow unwrapped pig carcass; a deep unwrapped pig carcass; a deep pig carcass wrapped in a tarp; a deep pig carcass wrapped in a cotton blanket; a deep pig carcass covered with a layer of rocks; and a deep pig carcass covered with a layer of lime. Two blank control graves, one shallow and one deep; were also constructed. Graves were monitored with EMI (electromagnetic induction meter) at 24 months and GPR at 30 months, using both the 500 and 250 MHz antennae. Results showed that the EMI was not a viable option in the detection of clandestine graves for the graves' soil type; graves were never detected during the monitoring period. On the other hand, GPR proved to be a favorable tool for monitoring controlled graves for a 30-month period; many scenarios were still detected at the end of the monitoring period. Of the imagery options available, reflection profiles were the preferred option. Burial scenarios with grave items (rocks, lime, blanket, and tarp) produced a more distinctive response for a longer period of time compared to unwrapped carcasses. Still, some months provided poor visibility of the imagery that was somewhat correlated with lower precipitation. Thus, dry soil or low soil moisture resulted in reduced demarcation of the graves. The 250 MHz results were more favorable for the shallow scenario. 33 figures, 34 references and appended supplementary data