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Suspect burial excavation procedure: A cautionary tale
Abstract
Geographic location, time of reporting and need for rapid evaluation contributed to a lack of intelligence concerning a suspect burial site in scrub woodland (approximately 15 km from the last known location of a missing person) in Northern Ireland. Police received reports of a subsiding 'grave', which was evaluated positively using GPR and victim recovery dogs (VRD). After 24h work, archaeological excavation showed a vertical-sided, stepped excavation on undisturbed clay with no inhumation. Subsequent research showed the feature to be an engineering trial pit. The GPR response was a water table and rocks, VRD were possibly reacting to disturbed ground. The work serves as a demonstration of good archaeological practice in suspect burial excavation, following a lack of landscape evaluation and poor overall intelligence.
... Even though GPR can help as part of a forensic investigation sequence [11], it has not been yet fully adopted in forensic science in Poland, because specialized training is necessary for acquiring, processing, and interpreting the data. Although some authors have achieved successful results under controlled conditions, such as in a cemetery test area [12] and over a simulated urban clandestine grave [13], 3D GPR has been rarely applied in real forensic cases because it used to require special training for both data acquisition and 3D data processing [14,15]. In addition, rough surfaces and time are often strong limitations in homicide investigations, and, therefore, most surveys are still carried out collecting 2D line scan data. ...
... been yet fully adopted in forensic science in Poland, because specialized tra sary for acquiring, processing, and interpreting the data. Although some achieved successful results under controlled conditions, such as in a cem [12] and over a simulated urban clandestine grave [13], 3D GPR has been in real forensic cases because it used to require special training for both d and 3D data processing [14,15]. In addition, rough surfaces and time are of itations in homicide investigations, and, therefore, most surveys are still c lecting 2D line scan data. ...
The international workshop ‘Forensic Search and Recovery of Clandestine Graves’ took place over two days in 2021 in Wroclaw, Poland. The goal of the workshop was to improve search methods and techniques related to the examination of clandestine burial sites. Geophysical methods were used by an international team of multi-disciplinary specialists to detect simulated burial sites. The training focused on testing methods, including Ground-Penetrating Radar (GPR), to verify the effectiveness of the methods in the search for two features representing clandestine burials. The forensic community in Central European countries, including Poland, has been slow to adopt these technologies due to controversial results. While geophysical research is successfully carried out in archaeological research and forensic contexts internationally, its application in the activities of the prosecutor’s office and the police in Poland has been relatively unsuccessful. This has resulted in several controversies related primarily to the erroneous expectations of how the methods are successfully applied. This may be the result of operator inexperience in applying these methods to the search for clandestine burials. This training paired an experienced GPR operator with law enforcement teams and archaeologists, leading to the successful discovery of simulated burials using GPR.
... Forensic investigators will generally incorporate a variety of methods as part of an interdisciplinary protocol when searching for clandestine graves and physical evidence associated with criminal activity. With the growing interest in the field of forensic geoscience (Davenport, 2001a;Fenning and Donnelly, 2004;Pye and Croft, 2004;Ruffell and McKinley, 2005;Morgan and Bull, 2007;Pye, 2007;Schultz, 2007a;Ruffell et al., 2009a;Schultz and Martin, 2012;Ruffell and McKinley, 2014), the use of geophysical tools as part of a multidisciplinary search protocol have become accepted search methods by criminal investigators. While early geophysical research concluded that ground-penetrating radar (GPR) was the most important geophysical tool for delineating forensic graves (France et al., 1992;France et al., 1997), more recently, it has been shown with controlled research that electrical resistivity is an important geophysical tool for forensic grave detection in certain soils that may limit the effectiveness of GPR (Jervis et al., 2009a;Jervis et al., 2009b;Pringle et al., 2012a;Pringle et al., 2016). ...
... In addition, if site characteristics are appropriate for this equipment, it is normally used to highlight smaller anomalous areas across a much larger survey area. Investigators can then focus follow-up testing over the smaller areas, that can include invasive methods, to confirm detection of a buried target, or to clear an area thought to contain a buried body or evidence so that additional searching can be directed elsewhere (Ruffell, 2005;Schultz, 2007a;Schultz and Dupras, 2008;Billinger, 2009;Ruffell et al., 2009a;Dupras et al., 2012;Schultz, 2012). ...
Geophysical techniques such as ground-penetrating radar (GPR) have been successfully used for forensic searches to locate clandestine graves and physical evidence. However, additional controlled research is needed to fully understand the applicability of this technology when searching for clandestine graves in various environments, soil types, and for longer periods of time post-burial. The purpose of this study was to determine the applicability of GPR for detecting controlled graves in a Spodosol representing multiple burial scenarios for Years 2 and 3 of a three-year monitoring period. Objectives included determining how different burial scenarios are factors in producing a distinctive anomalous response; determining how different GPR imagery options (2D reflection profiles and horizontal time slices) can provide increased visibility of the burials; and comparing GPR imagery between 500 MHz and 250 MHz dominant frequency antennae. The research site contained a grid with eight graves representing common forensic burial scenarios in a Spodosol, a common soil type of Florida, with six graves containing a pig carcass (Sus scrofa). Burial scenarios with grave items (a deep grave with a layer of rocks over the carcass and a carcass wrapped in a tarpaulin) produced a more distinctive response with clearer target reflections over the duration of the monitoring period compared to naked carcasses. Months with increased precipitation were also found to produce clearer target reflections than drier months, particularly during Year 3 when many grave scenarios that were not previously visible became visible after increased seasonal rainfall. Overall, the 250 MHz dominant frequency antenna imagery was more favorable than the 500 MHz. While detection of a simulated grave may be difficult to detect over time, long term detection of a grave in a Spodosol may be possible if the disturbed spodic horizon is detected. Furthermore, while grave visibility increased with the 2D reflection profiles, particularly with the 250 MHz antenna, the combination of both imagery options is recommended when evaluating GPR data during a search for a clandestine grave.
... The presence of conductive media, such as clay-rich subsoil, can attenuate the electromagnetic signal, and detecting underground features becomes difficult because the signal is not able to penetrate [7,11,12]. The use of GPR in forensic applications is a quite recently implemented practice, as it has only been used since the 1990s [13], but in recent years, the amount of published works with successful results in this context has increased [3][4][5]11,12,14,15]. ...
... In some cases, such as that of the bone remains, the identification was not clear from the field data. In this sense, although some studies in the specialized literature showed successful results when entire bodies were searched for using GPR [3,12,15,25], other authors have confirmed the existence of difficulties in the analysis and interpretation of the acquired data, when detecting skeletal remains in heterogeneous environments [5,10]. ...
Over the last few decades, the use of non-intrusive geophysical techniques, which allows for coverage of an entire crime scene in a reasonable amount of time, in forensic investigation has increased. In this study, we analyze the effectiveness of ground-penetrating radar (GPR) in forensics. Experimental scenes were simulated and some of the most commonly buried items in actual crime scenes were introduced, such as bone remains, guns and drug caches. Later, a GPR survey was conducted on the experimental grids with a 500 MHz antenna. The final purpose was to characterize the radar wave response expected for each set of remains to assist with its identification in later actual investigations. The results collected provided promising information that can be used when surveying real cases. Nevertheless, there were some interpretational difficulties regarding the sizes of the items and the electromagnetic properties of the materials. For these cases, finite-difference time-domain modeling was employed to achieve an advanced interpretation of the field data. The simulated models used were built from accurate geometric data provided by photogrammetric methods, which replicate the experimental scenes in fine detail. Furthermore, this approach allowed for the simulation of more realistic models, and the synthetic data obtained provided valuable information for assisting in the interpretation of field data. As a result of this work, it was concluded that GPR can be an effective tool when searching for a variety of materials during a crime scene investigation.
... In instances where the discovery of human remains is the aim of an investigation, such as when searching for the possible location of deposition in a missing persons case, VRDs are deployed in the search for human remains and possible clandestine burials. This can be on a singular or mass scale, for example, in individual cases such as locating the victims of the Moors Murders (Powell, 2023;Topping and Ritchie, 1989) and also to aid in finding extensive, multi deposition, IRA graves in Ireland (Powell, 2023;Ruffell et al., 2008). VRD have a highly precise sense of smell and can identify volatile organic compounds released through human decomposition, and thus can detect human remains that have been concealed, submerged in water, and buried up to 15 ft below the ground (K9 Patrol, 2022;Komar, 1999;Lasseter et al., 2003). ...
Emergency services professionals can encounter human remains on a frequent basis, therefore an ability to locate and recognize skeletal elements would be highly beneficial. While recognizing human bone has a clear utility to those involved in searching for remains, even for first responders who do not aid in the identification and analysis of remains, a basic knowledge of skeletal anatomy—and the ability to differentiate between human and animal bones—may assist both within the escalation process, and in understanding the scene. With this in mind, a workshop was commissioned by South Yorkshire Police in order to provide training on how to identify human bone in the field and differentiate between human and non-human bone. In total, 37 participants completed the workshop, with 100% completing a survey on the usefulness of the workshop regarding their own abilities before and after. Mann–Whitney U tests were run to determine differences in ability before and after the workshop to gauge whether participants noticed any improvement within their abilities. The testing showed that on average participants perceived an increase in their abilities after completing the workshop. Interestingly, when the test was broken into specific groups—Recovery Professionals and Identification Professionals—a difference in abilities both before and after the workshop was noted between groupings, suggesting that experience at crime scenes may aid in education. The results of this workshop show that training to not just first responders, but also to more senior personnel, was highly useful in widening their knowledge of skeletal material, which will help with any future encounters in the field.
... Similarly, some authors suggest that a trench should be excavated around the outline of the grave cut until the bottom of the grave has been reached. The graves should then be undercut and 28 Dupras et al. 2006;Hunter & Cox 2005;Ruffell et al. 2009;Hunter et al. 2013 a platform slid underneath so that the grave block can be transported to the laboratory to be excavated in controlled conditions 34 . The disadvantage of the pedestal method is that evidence might be damaged, lost or not noticed -and therefore destroyed -by digging the access trench. ...
... However, there is extensive literature demonstrating the potential of these specialists to process the complex scenarios involving human skeletal remains [1][2][3][4][5]. This has also been pointed out in numerous studies that include searching for and locating bones in the open, either on the surface [6], buried individually [7], or in multiple graves [8]. ...
This article presents a case study of a victim murdered in 2008 and found in a clandestine burial. The body was found in 2019 outside a rural residence in the province of Mendoza, Argentina. The article's objective is to demonstrate the relevance of having archaeologists and anthropologists on-site and the importance of multidisciplinary laboratory analysis as part of a continuous process of investigation. The search, location, exhumation, and interpretation of the burial was carried out using archaeological methods. In the laboratory, we reconstructed the biological profile and cause of death using forensic anthropology, dentistry, image diagnosis, and genetics. The postmortem interval and history were reconstructed from the entomological and taphonomic analyses. The individual's identity was confirmed and the evidence made it possible to locate and prosecute those responsible for the murder. Finally, the classic indicators of burial are discussed in relation to those found in the case study presented here. The unsystematic techniques used by the scientific police in cases of buried corpses are also critically assessed. We reflect on the importance of collecting adequate scientific evidence to support a legal case.
... However, GPR is not a good choice where the target is concealed underneath wet clays which limits its penetration depth to typically less than 1 m (Doolittle et al., 2002). Besides these limitations, GPR can provide the forensic experts with necessary information to achieve successful results, and thus considered one of the recently implemented method in criminological investigations (Mellet, 1992;Pringle et al., 2008;Ruffell and McKinley, 2005;Ruffell et al. 2009;Schultz et al., 2006;Schultz, 2007Schultz, , 2008. ...
Applied geophysics plays an important role in getting information beneath the ground surface. Ground penetrating radar (GPR) is one of the vital ground-based geophysical tool which gained considerable attention of law enforcement and other similar organizations dealing with criminal investigations worldwide particularly in developed countries. The current study discusses GPR application with a practical example to simulate the response from the excavated zone containing materials of criminological importance due to their resemblance to those buried items which are most frequently found in actual crime scenes. The main aim was to achieve the radar response expected in real scenario in order to facilitate the identification procedure in non-invasive way of the most commonly buried remains in crime scenes.
... Walkington (2010) also describes the importance of analysing suspected areas for forensic archaeology. However, it is important to note that excavations may not always be successful, with suspect burial areas in fact being due to something more benign, for example, a test trench for a potential site development as Ruffell et al. (2009b) document. ...
... The MS survey technique compared favourably to both GPR and resistivity in the sand dune scenario with it being much better on the foreshore as both the GPR and resistivity methods were poor in this depositional environment (see [37]). The 19th Century unmarked grave study showed that forensic targets over 100 years old could be detectable using the MS method although subsequent archaeological excavations have not been undertaken; other authors have used depressions and geophysics to successfully detect unmarked burials (e.g., [72]) but other studies have found that suspect burial positions may not, in fact, be what was suspected [73]. Clearly more geophysical data over marked burials with known burial dates would assist in determining if MS could be a useful technique in this arena and, indeed how long they would be detectable for ( Table 1). ...
There are various techniques available for forensic search teams to employ to successfully detect a buried object. Near-surface geophysical search methods have been dominated by ground penetrating radar but recently other techniques, such as electrical resistivity, have become more common. This paper discusses magnetic susceptibility as a simple surface search tool illustrated by various research studies. These suggest magnetic susceptibility to be a relatively low cost, quick and effective tool, compared to other geophysical methods, to determine disturbed ground above buried objects and burnt surface remains in a variety of soil types. Further research should collect datasets over objects of known burial ages for comparison purposes and used in forensic search cases to validate the technique.
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... It should be noted, however, that the use of GPR for locating burial sites should be done with caution. Ruffell et al. (10) conducted a similar excavation, also with negative results, leading them to conclude that their excavation demonstrated "good archaeological practice in suspect burial excavation, following a lack of landscape evaluation and poor overall intelligence." These cases highlight the fact that false positive results can be easily obtained from GPR data. ...
Cold case files present investigators with significant challenges in terms of the location and preservation of evidence, particularly when investigating the disap-pearances of missing persons who are likely to have been victims of homicide. This report details such challenges as experienced during a recent investigation con-ducted by the Edmonton Police Service in Alberta, Canada. The author acted as a consulting forensic anthropologist to assist in locating and recovering human remains that were presumed to have been buried under a concrete floor in the base-ment of a residential dwelling. Ground Penetrating Radar (GPR) technology was utilized in order to determine the location of the potential burial under the concrete. Despite positive results obtained through the GPR analysis, the excavation was met with negative results. This paper, therefore, cautions about false positive results when using GPR technology for locating possible burials under concrete. RÉSUMÉ Les dossiers de causes non résolues représentent de grands défis pour les enquêteurs en terme de lieu et de préservation d'éléments de preuve, particu-lièrement lors d'enquêtes de personnes portées disparues qui ont probablement été victimes d'homicides. Ce rapport raconte certains défis qui ont été rencontrés lors d'une récente enquête menée par la Edmonton Police Service en Alberta, Canada. L'auteur a agi en tant que conseiller anthropologue en sciences judiciaires pour assister à dénicher des dépouilles mortelles qui ont été supposément enterrées sous un plancher de béton dans un sous-sol d'un logement résidentiel. La technologie de radar par pénétration du sol (RPS) a été utilisée afin de déterminer l'endroit de l'enterrement potentiel sous le béton. Malgré des résultats positifs par analyses de RPS, l'excavation s'est avérée sans succès. Cet article fait donc une mise en garde de résultats positifs lorsque la technologie RPS est utilisée pour retrouver des enterrements potentiels sous le béton.
... Walkington (2010) also describes the importance of analysing suspected areas for forensic archaeology. However, it is important to note that excavations may not always be successful, with suspect burial areas in fact being due to something more benign, for example, a test trench for a potential site development as Ruffell et al. (2009b) document. ...
Geoscience methods are increasingly being utilised in criminal, environmental and humanitarian forensic investigations, and the use of such methods is supported by a growing body of experimental and theoretical research. Geoscience search techniques can complement traditional methodologies in the search for buried objects, including clandestine graves, weapons, explosives, drugs, illegal weapons, hazardous waste and vehicles. This paper details recent advances in search and detection methods, with case studies and reviews. Relevant examples are given, together with a generalised workflow for search and suggested detection technique(s) table. Forensic geoscience techniques are continuing to rapidly evolve to assist search investigators to detect hitherto difficult to locate forensic targets.
... Locating a clandestine grave or the exposed remains of a victim is sometimes a major obstacle for law enforcement personnel. Techniques for finding buried bodies include probing the soil and collecting soil samples, scanning with ground penetrating radar or geophysical electrical resistivity surveys, evaluating the landscape, and detecting the odor from cadaver decomposition with victim recovery (VR) canines [1][2][3][4][5][6][7]. Currently, none of these procedures for locating clandestine gravesites is very reliable and/or are useful for all scenarios. ...
Victims of crimes are often buried in clandestine graves. There are several techniques for finding buried bodies or the scattered remains of a victim; however, none of these methods are very reliable or work in all scenarios. One way to detect gravesoil is to detect the biochemical changes of the surrounding soil due to cadaver decomposition, for example, the release of nitrogenous compounds. A simple and low-cost way to detect these compounds is based on the reaction of alpha amino groups with ninhydrin to form Ruhemann's purple. This test for ninhydrin-reactive nitrogen (NRN) has, to date, only been performed by direct solvent extraction of soil samples. Here, we present a method that detects trace quantities of NRN in the headspace air above gravesoil. Our method is based on an improved purge and trap method developed in our lab for sampling low volatility compounds, as well as volatile compounds at trace quantities, by applying low temperature collection on short alumina-coated porous layer open tubular (PLOT) columns. We modified this method to sample the headspace air above gravesoil with a motorized pipetter and a PLOT column at ambient temperatures. We generated gravesoil using rat cadavers and local soil. Trace quantities of NRN were successfully detected in the headspace air above gravesoil. We report the quantities of NRN recovered for buried rats, rats laid on top of soil, and blank graves (no rats) as a function of time (weeks to months). This work is the first (and thus far, only) example of a method for detecting NRN in the vapor phase, providing another tool for forensic investigators to aid in locating elusive clandestine graves.
... Ground penetration radar (GPR) is a well accepted technique for the detection of clandestine graves since it was first successfully utilized in 1986 by Vaughn [1]. Despite the fact that GPR can help as part of a forensic investigation sequence [2], it has not been standardized by Spanish law enforcement because specialized training is necessary for acquiring, processing and interpreting the data. On the other hand, the advantages of using non-intrusive methods, such as GPR, are preservation of the crime scene, little destruction of forensic evidence and, therefore, the possibility of reconstructing events at the scene [3]. ...
In the present work we show a forensic case study carried out in a mountainous environment. Main objective was to locate a clandestine grave which is around 10-20 years old and contains human remains of one individual and a metallic tool, probably a pick. Survey design started with an experimental burial of a pick at the expected depth (1m) as well as the calculation of synthetic radargrams in order to know if the 250MHz antenna was suitable for its detection and to have a record of the reflection of the pick. Conclusions extracted from the experiments together with rough terrain conditions suggested the use of the 250MHz antenna which allowed a good compromise between target detection and dense grid acquisition of an extensive survey area.
This study explores the current state of research in modeling and simulating geoelectrical properties of buried objects, focusing on 2D and 3D techniques. The study evaluated the ability of geoelectrical data to determine geometrical structures and analyze resistivity values of geological features using three models:1) a steel buried object model; 2) a brick model representing a small-scale normal fault, and 3) a foam object model. The study assessed geoelectrical data quality and dependability using Pearson correlation coefficients for both synthetic and laboratory models. Wenner arrays are used to accurately detect the depth of buried steel objects, whereas Dipole-Dipole arrays are effective in locating faults. Additionally, the study examined Wenner and Dipole-Dipole arrays’ usefulness for buried object cases, highlighted how multiple arrays may be used to identify foam objects, and emphasized the importance of array selection for specific surveys. The study emphasizes the importance of considering 3D effects, choosing the right array, and being aware of the limitations of two-dimensional electrical resistivity tomography 2DERT in accurately representing geoelectrical structures in various subsurface environments.
This represents one of several sections of "A Bibliography Related to Crime Scene Interpretation with Emphases in Geotaphonomic and Forensic Archaeological Field Techniques, Nineteenth Edition" (The complete bibliography is also included at ResearchGate.net.). This is the most recent edition of a bibliography containing resources for multiple areas of crime scene, and particularly outdoor crime scene, investigations. It replaces the prior edition and contains approximately 10,000 additional citations. As an ongoing project, additional references, as encountered, will be added to future editions.
Regardless of the search method which brings the investigator to a site believed to contain buried evidence, there is only one means, to date, of precisely determining what that spot contains. In making that determination, it is as important to recover and document the precise position of associated and trace evidence as it is the primary piece of evidence. It has been the compiler’s observation that law enforcement examinations of buried body crime scenes, in particular, tend to concentrate on the location and removal of the primary evidence - the body without consideration of those archaeological (geotaphonomic) features which explain its context. There is considerably less “excitement”, and therefore emphasis, on associated and trace elements. This can be extremely unfortunate given the value of such evidence in determining when, why, how, and by whom the body was deposited. The effects of time and environment on the post-depositional history of remains represent the bases of taphonomy. The lack of similar emphasis on recognizing and collecting associated and trace evidence caused the compiler to consider geotaphonomy as a legitimate area of research in forensic science.
Geotaphonomy is defined as the study of the geophysical characteristics of, and changes in, surface to subterranean features associated with the interment of buried evidence. The concept of forensic geotaphomomy developed out of a realization that investigators of clandestine graves, or other buried evidence crime scenes, lacked precedent demonstrating the possible geophysical features or conditions which could aid interpreting subterranean scenes. Although they are seldom noticed at contemporary crime scenes, many of these conditions are the bases of archaeological tenets. In geotaphonomy the features comprise six areas or classes of evidence which are introduced during and after the original excavation and backfilling of subterranean pits. The six classes of geophysical evidence include stratification, tool marks, bioturbation, sedimentation, compression/depression, and internal compaction.
In order to record the context of buried evidence, it is paramount that proper archaeological excavation techniques be applied. Often, what is described in media accounts as “archaeological excavation” for the remains of a homicide victim, are in fact merely “digging up” the remains. For the recovery to truly be archaeological, two immutable principles must be followed: the excavation must be systematic, and it must include the recognition and documentation of all contextual, or environmental, artifacts. Toward providing resources which describe, affect, and/or suggest methods in archaeology, the following citations were compiled. Included are a few specific site reports with which the compiler had access or was aware. It should be understood that thousands of such reports are prepared by academic and engineering institutions around the world. They continue to be drafted as sites of historical and archaeological significance are excavated. It would not be feasible to include even a fraction of these reports. What becomes readily apparent after a review of the following citations is the diversity of search settings, and the need to form equally diverse plans toward the excavation of these sites. As long as the principles of systematic excavation and contextual recovery are maintained, flexible excavation strategies will remain appropriate. The archaeologist receives training in soil and botanical sciences in order to understand the formation processes of those matrices into which cultural features intrude. For that reason, the reader or researcher is also referred to the categories of Geoarchaeology and Soil Science, as well as Botany and Related Areas. (1711 citations)
This paper is a review of methods related to assessment of construction details and material properties using of GPR. The focus is on recent research activities of the Project “Innovative procedures for effective GPR inspection of construction materials and structures” (project 2.4) in COST Action TU1208. The electromagnetic properties of investigated media are interesting because they reflect physical features of the materials (e.g. their composition), enabling a non-invasive inspection of their condition. Moreover, the assessment of electromagnetic properties (e.g. wave velocity) is an inherent part of any GPR structural study necessary for correct depth determination or amplitude interpretation. As a result of the review major directions of research are highlighted and some benefits and limits of different approaches are described.
In addition to traditional techniques, a broad range of science and technological expertise is applied in forensics, including geophysics. Forensic geophysics is used to locate, map and study buried objects or targets beneath soil or water using geophysical tools. Various geophysical techniques are used in forensic investigations, in which the buried targets may include varied items, such as weapons, metal barrels, human remains and bunkers. Geophysical methods have the capability to aid investigators in searching for and recovering such targets because large areas can be investigated non-destructively and rapidly. An area of interest may be the location of an illegal burial or where a suspect has attempted to hide a target item underground. When there is a contrast between the physical properties of a target and those of the material in which it is buried, it is possible to accurately locate the target item. Geophysical methods can also be used to recognize evidence from humans or excavation activities, both recent and older.
Ground penetrating radar (GPR) is one of the most useful geophysical tools for investigating targets beneath the soil. This technique uses radio waves to map structures and features buried in the ground. A radar-transmitting antenna emits an electromagnetic impulse that can be reflected or scattered by a dielectric discontinuity in the ground and gathered by a receiving antenna.
This technique has yielded impressive results in various applications, such as archaeology, environmental science and engineering; it has recently been applied to forensics with good results, but the technique can still be improved.
The aim of this chapter is to highlight the potential of GPR, specifically how it may be helpful during forensic investigations to quickly provide high-quality results. The method is very useful, but it is necessary to understand its underlying principles and procedures to obtain the best results. In this paper, laboratory-scale and field-scale experimental data are presented to provide a better understanding of the strengths and weaknesses of GPR.
This Chapter deals with a compilation of published works in the frame of the applications of the GPR for humanitarian assistance and security. The fields of application, in which the technique has experienced more advances, are the detection of mines and unexploded ordnances, as well as the location of underground spaces. Different types of defensive constructions were built throughout history to protect people from natural catastrophes, aerial bombardments and other attacks. Moreover, the use of the GPR technology in rescue operations is considered by including the main contributions in locating human remains or living victims in disaster areas. An overview of the main GPR works in humanitarian missions and their results are therefore mentioned. Specific systems, methodologies and processing algorithms developed in these applications are also analysed. As result, the method has shown significantly benefits when compared to other traditional searching methods.
The current status and potential scope of archaeological approaches to forensic casework in New Zealand is critically reviewed. The development and current practice of forensic archaeology is outlined, demonstrating that the discipline has been successfully incorporated into crime- and disaster-scene work in other countries as well as the international humanitarian arena. Despite the application of ostensibly archaeological techniques to clandestine graves by Police and ESR forensic scientists, currently forensic archaeology is absent in New Zealand. Factors including low homicide rates, the absence of suitably qualified forensic archaeologists, a lack of education around what forensic archaeology is, and economic constraints are considered as possible explanations. International evidence shows that any case that requires physical spadework for the recovery of evidence is a case where archaeology can contribute positively, and the low frequency of such situations need not undermine the importance of maximising evidential recovery and interpretation and employing best practice. It is argued that the framework already exists for archaeological approaches to forensic casework in New Zealand, but has only to be integrated with greater training, cooperation and education.
Forensic geology, forensic geoscience and geoforensics (see the text for definitions) are largely concerned with searches for buried objects or the use of sediment and soil analysis as evidence. Geophysics, remote sensing, geostatistics, geochemistry and geomorphology are considered part of these disciplines. Traditional outcrop geology is not often considered, with very few publications considering the role of mapped and logged geology. This work comprises a review of the few published works, followed by a range of case studies that demonstrate how traditional, outcropscale drift and solid geology can be used in forensic geology. These include: using geology in the search for buried explosives and human remains; the logging of solid and drift geology for analysis of disputed rock quality; and modelling groundwater flow from an illegal landfill site. Geological mapping may assist in limiting a search area or in understanding what failed in a search or forensic investigation. The scale of forensic geology discussed bridges the gap between the two traditions of forensic geology outlined above: that of searching large areas of ground and trace evidence analysis.
Implementing controlled geophysical research is imperative to understand
the variables affecting detection of clandestine graves during real-life
forensic searches. This study focused on monitoring two empty control
graves (shallow and deep) and six burials containing a small pig carcass
(Sus scrofa) representing different burial forensic scenarios: a shallow
buried naked carcass, a deep buried naked carcass, a deep buried carcass
covered by a layer of rocks, a deep buried carcass covered by a layer of
lime, a deep buried carcass wrapped in an impermeable tarpaulin and a
deep buried carcass wrapped in a cotton blanket. Multi-frequency, ground
penetrating radar (GPR) data were collected monthly over a 12-month
monitoring period. The research site was a cleared field within a wooded
area in a humid subtropical environment, and the soil consisted of a
Spodosol, a common soil type in Florida. This study compared 2D GPR
reflection profiles and horizontal time slices obtained with both 250
and 500 MHz dominant frequency antennae to determine the utility of both
antennae for grave detection in this environment over time. Overall, a
combination of both antennae frequencies provided optimal detection of
the targets. Better images were noted for deep graves, compared to
shallow graves. The 250 MHz antenna provided better images for detecting
deep graves, as less non-target anomalies were produced with lower radar
frequencies. The 250 MHz antenna also provided better images detecting
the disturbed ground. Conversely, the 500 MHz antenna provided better
images when detecting the shallow pig grave. The graves that contained a
pig carcass with associated grave items provided the best results,
particularly the carcass covered with rocks and the carcass wrapped in a
tarpaulin. Finally, during periods of increased soil moisture levels,
there was increased detection of graves that was most likely related to
conductive decompositional fluid from the carcasses.
The data provided by three different measurement instruments, terrestrial laser scanning, image measurement from rectified photographs and 3D ground-penetrating radar, are compared and analysed in this work. For this purpose, an experimental grave is prepared using human bone remains and a pig carcass.A comparison of the geometrical data collected from the bone remains using laser scanning and single-image rectification show an agreement better than 4% for bones longer than 75 mm, which confirms the possibility of using the low cost image measurement technique for forensic purposes.The volume and weight of the pig carcass is also evaluated using the laser scanning data and a surface model fitted to the point cloud. The obtained result matches with the real data provided by the veterinarian. However, care must be taken to avoid the occlusions of the laser data, which could artificially increase the volume.The ground-penetrating radar survey clearly reveals the place where the pig is buried. The cross-sectional area is evaluated. The volume of the pig detected by GPR was determined and compared with the value obtained from the laser scanning. The results show a difference of about 25%.The ground-penetrating radar survey also shows some evidence of the cranium from the bone remains in the grave. However, the results are not clear, which demonstrates that the reliability of this technique decreases when the tissues of the cadaver are completely degraded.
IntroductionForensic Archaeology in EuropeThe Role of the Forensic Archaeologist in the UKThe Role of the Forensic ArchaeologistWhy an Archaeologist?Conclusion
AcknowledgmentsReferences
Forensic personnel generally use basic all-metal detectors for weapon searches because of their ease of use and cost efficiency. For ferromagnetic targets, an alternative easy to use and low-cost geophysical tool is a magnetic locator. The following study was designed to demonstrate the effectiveness of a common, commercially available magnetic locator in forensic weapon searches by determining the maximum depth of detection for 32 metallic forensic targets and testing the effects of metallic composition on detection. Maximum depth of detection was determined for 16 decommissioned street-level firearms, six pieces of assorted scrap metals, and 10 blunt or bladed weapons by burying each target at 5-cm intervals until the weapons were no longer detected. As expected, only ferromagnetic items were detected; weapons containing both ferromagnetic and nonferromagnetic components were generally detected to shallower depths. Overall, the magnetic locator can be a useful addition to weapon searches involving buried ferromagnetic weapons.
Since ground-penetrating radar (GPR) has become a popular search option for clandestine graves, controlled research is essential to determine the numerous variables that affect grave detection. The purpose of this study was to compare GPR reflection profiles of a controlled grave containing a large pig carcass and a blank control grave at 6 months interment in a Spodosol, which is a common soil type in Florida. Data collection was performed in perpendicular orientations over the graves using both 500 and 250 MHz antennae. Since reflection profiles are used to make initial in-field assessments during a forensic search, it is important for controlled research to evaluate this imagery option. Overall, it was possible to detect the grave containing a pig carcass at 6 months interment that was buried in a Spodosol using both the 500 and the 250 MHz antennae. While the 500 MHz antenna provided more detail within the grave containing a pig carcass, including detecting a soil disturbance and the pig carcass, the 250 MHz antenna also provided excellent imagery. Either antenna would provide optimal results for the type of soil that was sampled. Furthermore, it may be possible to locate actual forensic graves in this soil type when no response from the body is noted, as there may be a discernable response from the disturbed soil within the grave shaft and a noticeable disruption of the spodic horizon. Finally, survey orientation may also affect detection. Since data collection performed in two perpendicular directions detected the pig carcass and the grave floor of the control grave, data collection for an actual search involving a body interred for a long postmortem interval should be performed in both directions when time permits.
Incorporating geophysical technologies into forensic investigations has become a growing practice. Oftentimes, forensic professionals rely on basic metal detectors to assist their efforts during metallic weapons searches. This has created a need for controlled research in the area of weapons searches, specifically to formulate guidelines for geophysical methods that may be appropriate for locating weapons that have been discarded or buried by criminals attempting to conceal their involvement in a crime. Controlled research allows not only for testing of geophysical equipment, but also for updating search methodologies. This research project was designed to demonstrate the utility of an all-metal detector for locating a buried metallic weapon through detecting and identifying specific types of buried metal targets. Controlled testing of 32 buried targets which represented a variety of sizes and metallic compositions included 16 decommissioned street-level firearms, 6 pieces of assorted scrap metals, and 10 blunt or bladed weapons. While all forensic targets included in the project were detected with the basic all-metal detector, the size of the weapon and surface area were the two variables that affected maximum depth of detection, particularly with the firearm sample. For example, when using a High setting the largest firearms were detected at a maximum depth of 55 cm, but the majority of the remaining targets were only detected at a maximum depth of 40 cm or less. Overall, the all-metal detector proved to be a very good general purpose metal detector best suited for detecting metallic items at shallow depths.
The search for buried remains frequently includes visual assessment of surface features, trained dogs, and sophisticated geophysical remote sensing techniques. Nonintrusive, electronic survey equipment, such as the proton magnetometer, ground penetrating radar, and electrical resistivity, have yielded good results. However, under certain field conditions a simple, less expensive, relatively noninvasive tool-the probe-is effective. The probe, when used by an experienced investigator, provides a variety of information in a short amount of time, facilitates excavation, and minimizes damage to a burial. This paper offers examples of the application of a probe in forensic cases in urban and rural settings and in the detection of historic burials. Examples include the location of four individuals killed during the raid on the Branch Davidian Compound in Mount Carmel, Texas, and the search for burials in cemeteries that had been desecrated.
Shallow electromagnetic (EM) and ground-penetrating radar (GPR) surveys were conducted in an area north of Auckland, New Zealand to assist the search for human remains. The body had been buried for almost 12 years in a plantation forest that was irregularly disrupted and modified by tree harvesting and the partial removal of stumps. EM identified anomalous areas of potential interest, because a target need only be nearby to generate an EM response. GPR was then used to map subsurface layering, layering disruption, and buried objects, immediately adjacent to an EM anomaly. Because of the nature of the site, numerous geophysical anomalies were present. GPR was particularly sensitive to site disturbance resulting from the forestry operations. An isolated EM anomaly on the fringes of an expanded survey area was coincident with the location of the body. Whether for criminal investigations or for archaeological work, a combination of geophysical techniques is recommended.
Forensic Recovery of Human Remains
- T L Dupras
- J J Schultz
- S M Wheeler
- L J Williams
T.L. Dupras, J.J. Schultz, S.M. Wheeler, L.J. Williams, Forensic Recovery of Human Remains, Taylor & Francis Group, New York, 2006, 232 pp..
Forensic Archaeology: Advances in Theory and Practice, Rou-tledge
- J Hunter
- M Cox
J. Hunter, M. Cox, Forensic Archaeology: Advances in Theory and Practice, Rou-tledge, Taylor & Francis Group, London, 2005, 233 pp..
Forensic geophysical survey
- P Cheetham
P. Cheetham, Forensic geophysical survey (Chapter 3), in: J. Hunter, M. Cox (Eds.), Forensic Archaeology: Advances in Theory and Practice, Routledge, Taylor & Francis Group, London, 2005, pp. 62–95.
Forensic geophysical survey (Chapter 3)
- Cheetham