Exploring non-invasive approaches to assist in the detection of clandestine human burials: developing a way forward

Abstract

The analyses of physical evidence recovered from clandestine single and mass graves have been demonstrated to be of significant evidential and/or investigative value for both court purposes and humanitarian investigations. The detection of these types of graves is, therefore, pivotal to forensic investigations. This article reviews different remote and ground-based methods that have been used to attempt to detect deliberately concealed burial sites and summarizes the experimental research that has, to date, been undertaken in order to improve grave detection. The article then presents the preliminary findings of research being undertaken at the Australian Facility for Taphonomic Experimental Research (AFTER). This research, the first of its kind to be undertaken in the southern hemisphere, is based on experimental single and mass graves using human cadavers. The research is centred on current remote sensing methods and techniques combined with the analysis of the effects of below-ground temperature and moisture and ground-based weather data. It is hoped that identifying successful sensors and detectors will be beneficial to national and international agencies that are involved in forensic as well as humanitarian investigations that require the detection of deliberately concealed gravesites.

A Low Cost Approach to Disturbed Soil Detection Using Low Altitude Digital Imagery from an Unmanned Aerial Vehicle

“…Even though aerial photographs have been assessed in the literature [18] as an effective tool for detecting unmarked and clandestine graves within rural areas, all remote sensing methods have limited capabilities in heavy woodland (with the exception of some laser scanning technologies able to penetrate vegetation, however, the ground plane can only be extracted during post processing [20]). With regard to this, UAV technology has advanced manoeuvrability compared to manned aircraft and National Police Air Service (NPAS) helicopters, which may make UAVs more suited to operate in some sparsely wooded environments.…”

“…Yet, current methods of clandestine burial searches remain costly as police resources are spent on determining grave location guided by witness statements [4,12,19]. Due to this, state-of-the-art remote sensing techniques such as aerial photography using Unmanned Aerial Vehicles (UAVs) are replacing the reliance upon witness statements by determining the approximate grave location through the rapid detection of visual anomalies [18,20,21]. In this context, remote sensing is the acquisition of data about an object or scene without physically touching it [22].…”

“…In this context, remote sensing is the acquisition of data about an object or scene without physically touching it [22]. Current remote sensing techniques used in the search for clandestine graves include the use of sensors mounted on-board satellites, manned aircraft and UAVs, for the purpose of capturing imagery or collecting other data for analysis [20]. Satellite imagery is the most traditional remote sensing technique used to detect ground disturbance [23], previously, satellite imagery has been used with success to detect burials in mass grave scenarios [19,24,25].…”

“…However, whilst the image resolution obtained from full-scale aircraft is often much better suited compared to satellites, manned aircraft are still operationally costly and access is limited amongst law enforcement agencies. Despite these limitations, in an investigative context, airborne systems are still more commonly favoured over traditional geophysical techniques [32] as they limit unnecessary footfall, which minimizes crime scene alteration [20].…”

“…Due to its capability for fast deployment with limited demands upon police resources. While the literature surrounding the use of UAVs for clandestine burial detection is generally limited [20,21,35], questions have been raised regarding their practical usage in large scale homicide investigations, with regards to the detection of buried remains. As such, Murray et al (2018) have written an exhaustive review on the use of the use of UAVs and multiple sensors for the detection of clandestine graves and surface remains [21].…”