The use of geoscience methods for terrestrial forensic searches

Soils and sustainable development goals of the United Nations: An International Union of Soil Sciences perspective

GPR and bulk ground resistivity surveys in graveyards: Locating unmarked burials in contrasting soil types

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.

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

The use of remote-sensing images is becoming common practice in the fight against environmental crimes. However, the challenge of exploiting the complementary information provided by radar and optical data, and by more conventional sources encoded in geographic information systems, is still open. In this work, we propose a new workflow for the detection of potentially hazardous cattle-breeding facilities, exploiting both synthetic aperture radar and optical multitemporal data together with geospatial analyses in the geographic information system environment. The data fusion is performed at a feature-based level. Experiments on data available for the area of Caserta, in southern Italy, show that the proposed technique provides very high detection capability, up to 95%, with a very low false alarm rate. A fast and easy-to-use system has been realized based on this approach, which is a useful tool in the hand of agencies engaged in the protection of territory.

Detection of environmental hazards through the feature-based fusion of optical and SAR data: a case study in southern Italy

Abstract:  This study provides forensic search teams with systematic geophysical monitoring data over simulated clandestine graves for comparison to active cases. Simulated “wrapped” and “naked” burials were created. Multigeophysical surveys were collected over a 3‐year monitoring period. Bulk ground resistivity, electrical resistivity imaging, multifrequency ground‐penetrating radar (GPR), and grave and background “soil‐water” conductivity data were collected. Resistivity surveys revealed the naked burial had consistently low‐resistivity anomalies, whereas the wrapped burial had small, varying high‐resistivity anomalies. GPR 110‐ to 900‐MHz frequency surveys showed the wrapped burial could be detected throughout, with the “naked” burial mostly resolved. Two hundred and twenty‐five megahertz frequency GPR data were optimal. “Soil‐water” analyses showed rapidly increasing (year 1), slowly increasing (year 2), and decreasing (year 3) conductivity values. Results suggest resistivity and GPR surveys should be collected if target “wrapping” is unknown, with winter to spring surveys optimal. Resistivity surveys should be collected in clay‐rich soils.

/pdf/geophysical-monitoring-of-simulated-clandestine-graves-using-4vpkn5n4sw.pdf

Geophysical Monitoring of Simulated Clandestine Graves Using Electrical and Ground-Penetrating Radar Methods: 0-3 Years After Burial*,†: GEOPHYSICAL MONITORING OF SIMULATED CLANDESTINE GRAVES

The use of magnetic susceptibility as a forensic search tool.

Abstract Near-surface geophysical techniques should be routinely utilized by law enforcement agencies to locate shallowly buried forensic objects, saving human and other resources. However, there has been little published research on optimum geophysical detection method(s) and configurations beyond metal detectors. This paper details multi-technique geophysical surveys to detect simulated unmarked illegal weapons, explosive devices and arms caches that were shallowly buried within a semi-urban environment test site. A concrete patio was then overlaid to represent a common household garden environment before re-surveying. Results showed that the easily utilized magnetic susceptibility probe was optimal for target detection in both semi-urban and patio environments, while basic metal detector surveys had a lower target detection rate in the patio scenario with some targets remaining undetected. High-frequency (900 MHz) ground penetrating radar antennae were optimum for target detection in the semi-urban environment, while 450 and 900 MHz frequencies had similar detection rates in the patio scenario. Resistivity surveys at 0.25 m probe and sampling spacing were good for target detection in the semi-urban environment. 2D profiles were sufficient for target detection, but resistivity datasets required site de-trending to resolve targets in map view. Forensic geophysical techniques are rapidly evolving to assist search investigators to detect hitherto difficult-to-locate buried forensic targets.

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Comparison of magnetic, electrical and ground penetrating radar surveys to detect buried forensic objects in semi-urban and domestic patio environments

J.D. Hansen

Papers

The use of geoscience methods for terrestrial forensic searches

Geophysical Monitoring of Simulated Clandestine Graves Using Electrical and Ground-Penetrating Radar Methods: 0-3 Years After Burial*,†: GEOPHYSICAL MONITORING OF SIMULATED CLANDESTINE GRAVES

GPR and bulk ground resistivity surveys in graveyards: Locating unmarked burials in contrasting soil types

The use of magnetic susceptibility as a forensic search tool.

Comparison of magnetic, electrical and ground penetrating radar surveys to detect buried forensic objects in semi-urban and domestic patio environments