Long‐term Geophysical Monitoring of Simulated Clandestine Graves using Electrical and Ground Penetrating Radar Methods: 4–6 Years After Burial

Abstract

This ongoing monitoring study provides forensic search teams with systematic geophysical data over simulated clandestine graves for comparison to active cases. Simulated “wrapped,” “naked,” and “control” burials were created. Multiple geophysical surveys were collected over 6 years, here showing data from 4 to 6 years after burial. Electrical resistivity (twin electrode and ERI), multifrequency GPR, grave and background soil water were collected. Resistivity surveys revealed that the naked burial had low‐resistivity anomalies up to year four but then difficult to image, whereas the wrapped burial had consistent large high‐resistivity anomalies. GPR 110‐ to 900‐MHz frequency surveys showed that the wrapped burial could be detected throughout, but the naked burial was either not detectable or poorly resolved. 225‐MHz frequency GPR data were optimal. Soil water analyses showed decreasing (years 4 to 5) to background (year 6) conductivity values. Results suggest both resistivity and GPR surveying if burial style unknown, with winter to spring surveys optimal and increasingly important as time increases.

An Experiment to Characterize the Decomposer Community Associated with Carcasses (Sus scrofa domesticus) on Oahu, Hawaii

“…These processes include gross postmortem changes (e.g., livor mortis, marbling, bloating), autolysis, putrefaction, insect larval development, scavenging activity, and many others. Taphonomy is relevant to medicolegal death investigation because proper interpretation of decomposition processes can accomplish investigative goals such as establishing the cause of death , locating clandestine graves , and estimating postmortem interval . An ecological approach to studying and applying taphonomy is often implemented because many decomposition processes are biologically mediated.…”

The Search for “Fred”: An Unusual Vertical Burial Case,

“…These control studies have shown that the geophysical responses in active cases could be predicted, although responses seem to vary both temporally after burial and between different study sites. A few studies have also collected repeat (time-lapse) geophysical surveys over controlled experiments (e.g., [18,[47][48][49][50][51][52][53][54][55][56][57]), which have documented temporal changes in geophysical responses over their study periods.…”

Preliminary hand-held thermal imaging results of sequential monitoring of a simulated deceased individual on terrestrial ground

“…The local soil is a sandy loam with nearby borehole records (27) with a bedrock of Carboniferous (Westphalian) Butterton Sandstone bedrock present at ~2.5 m below ground level (bgl). This site has been previously used for forensic geophysical studies (27)(28)(29)47) but these are downslope of this investigation site so avoiding any soil contamination issues.…”

“…The use of pig cadavers as human analogues is well established in forensic science studies as they have similar chemical compositions, body sizes, tissue-to-body fat ratios, gut fauna, skin ⁄ hair types, and emissivity value to humans (27,28,(48)(49)(50). At the current research site their use has been approved by the Department for Environment, Food & Rural Affairs (DEFRA) and the School's Ethics Committees.…”

“…Recent forensic research has used control studies to determine optimal body detection method(s) and equipment configuration(s). Results can be highly variable, depending upon a large number of factors, the most important being postmortem interval (PMI), body wrapping, local soil type, vegetation and climate (21)(22)(23)(24)(25)(26)(27)(28)(29)(30).…”