Keeping the pieces together: comparison of mass grave excavation methodology

Mass graves are a complex and confusing mix of bodies, body parts, soils, artifacts, and other feature evidence. Forensic investigations of these complex crime scenes should attempt to maximize the collection of evidence, which includes the mortal remains, in their best possible condition as they were deposited within the graves. Two standard methods of mass grave excavation were examined with the aim of identifying the better approach. Two experienced teams using different methodologies excavated two separate but very comparable mass graves located in the same area. Single disarticulated skeletal elements not associated with a body at the time of removal from the grave were categorized and their counts analyzed to evaluate the efficiency of the differing excavation methodologies. The methodologies used were the 'pedestal' method, which focuses on the body mass, and the 'stratigraphic' method, in which the grave feature and contents are conjointly excavated. The first grave (Grave A), excavated using the 'pedestal' method, was observed to have a disproportionately larger amount of unassociated bones than did the second (Grave B), which used the 'stratigraphic' method. Chi-square (chi2) goodness-of-fit and contingency tests were performed on the total numbers of recorded elements and different categorical groups of bones, based on size and shape, in each grave. Results demonstrate that significantly greater numbers of unassociated elements resulted from the excavation of Grave A using the pedestal method, both in total number of disarticulated bones as well as within 'large' and 'medium' categories. Conversely 'small' skeletal elements were recovered at a higher rate in Grave B. The lower 'large' and 'medium' bone production rates from Grave B indicate that the stratigraphic method better maintained the provenience and articulation of remains than did Grave A, while the higher 'small' bone recovery rate may point to better recovery techniques of Grave B's excavation team.     

Forensic DNA Challenges: Replacing Numbers with Names of Fosse Ardeatine’s Victims*

Abstract: The Fosse Ardeatine massacre was a mass execution carried out in Rome on March 24, 1944 by Nazi German occupation troops during the Second World War as a reprisal for a partisan attack conducted on the previous day in central Rome. The 335 civilians were taken to the “Cave Ardeatine” and they were shot. Only 323 corpses out of 335 have been identified. The aim of this work is the genetic and anthropological analysis of the remains exhumed from grave number 329 of Fosse Ardeatine’s Shrine to assess their identity. So far, such remains have been supposed to belong to MM but mitochondrial analysis excluded a biological relationship to two living maternal relatives. Our analysis indicated that remains recovered in grave number 329 do not belong to MM. This result suggests that genetic analysis of the remains should be also applied to the other 12 unknown corpses to elucidate their identity.     

Time-lapse resistivity surveys over simulated clandestine graves

The aim of this study was to develop a better understanding of how electrical resistivity surveys can be used to locate clandestine graves. Resistivity surveys were conducted regularly over three simulated clandestine graves containing a pig cadaver, no cadaver and a pig cadaver wrapped in tarpaulin, respectively. Additionally, soil and groundwater samples were collected from two more simulated graves outside the survey area. The grave containing a pig cadaver was detectable from a low resistivity anomaly in the survey data. Groundwater data suggest that the resistivity anomaly associated with the surveyed pig grave was caused by a localised increase in groundwater conductivity. Wrapping a cadaver was found to initially change the resistivity response of a grave to a high resistivity anomaly. Resistivity surveys did not detect the disturbed soil in the grave that did not contain a cadaver. Although soil samples showed grave soil to be more porous than undisturbed soil, the lack of response from the grave that did not contain a cadaver suggests that disturbed soil was not responsible for the resistivity anomalies observed in this study. Resistivity surveys successfully detected all graves containing cadavers throughout the study, whilst also showing the potential to eliminate the need for mass excavation in a genuine search.     

Investigation of Different Ways in Which the CODIS 7.0 May be Used in Mass Disaster Identification

DNA analysis is a key method for the identification of human remains in mass disasters. Reference samples from relatives may be used to identify missing persons by kinship analysis. Different methods of applying the CODIS in disaster victim identification (DVI) were investigated. Two searches were evaluated: (i) relating family relatives to a pedigree tree (FPT) and (ii) relating unidentified human remains to a pedigree tree (UPT). A joint pedigree likelihood ratio (JPLR) and rank were calculated for each search. Both searches were similar in average JPLR and rank. In exceptional cases, namely the existence of a mutation different from the CODIS model, a nonbiological father, a mistake in STR, or incorrect profile association, the UPT search returned one true rank, whereas the FPT search returned no results. This paper suggests a novel strategy to overcome these limitations and increase efficiency in conducting identification of mass disaster victims.     

Guidelines for international forensic bio-archaeology monitors of mass grave exhumations

The systematic exhumation of mass graves is becoming a frequent occurrence globally. Historically, it has been mostly anthropologists with their particular expertise in osteology that have been engaged by non-governmental organizations (NGO) to monitor mass grave exhumations and postmortem examinations, conducted by a host country or international forensic team, to ensure competence and a concern for justice. The excavation of graves and examination of their contents for the purposes of personal identification of victims and/or collection of evidence for prosecution require the creation of standards that meet international concerns for forensic investigation of the highest quality. However, many anthropologists are not experienced with large sites; do not have much, if any, expertise in archaeology; and are not equipped by training to assess the quality of a forensic pathologist's autopsy. This contribution is directed to both the NGO and the bio-archaeologist who are involved in the exhumation of mass graves. The experience and skills appropriate for the bio-archaeological monitor are outlined; similarly, the policies and standard operating procedures (SOP's) of the NGO that will enable the bio-archaeologist to perform their task are detailed. It is becoming increasingly clear that how a grave site was created, filled, and concealed, along with subsequent processes of site formation (e.g. slumping, robbing, animal scavenging and taphonomic alteration), require the expertise of a forensic archaeologist to discover and record site complexity along with associated forensic evidence. Similarly, the bodies themselves which are often skeletonized, fragmented and commingled pose challenges for the anthropologists and pathologists whose postmortem examinations must be critically evaluated. A model protocol for observations to make at the site as well as at the mortuary facility is provided to guide the monitor and to provide a structure for reports which are of standardized content suitable for international agencies concerned with mass grave investigation.     

Testing Application of Geographical Information Systems,Forensic Geomorphology and Electrical Resistivity Tomography to Investigate Clandestine Grave Sites in Colombia,South America

Colombian forensic investigators required assistance locating clandestine burials of missing persons related to human right atrocities from 14 years ago. Geoscientific search methods were trialled, including a predictive spatial statistical model, using various input and database information, to select the most likely grave locations in difficult mountainous terrain. Groundwork using forensic geomorphology, near-surface geophysics (ERT) and subsequent probing identified suspect burial positions. One site was in mountainous terrain and the other in former school grounds, both difficult to access and in poor weather conditions. In the mountainous area, a negative resistivity anomaly area was identified and intrusively investigated, found to be a buried rock. In school grounds, after MESP and intelligence were used to identify a burial site, surface depressions were identified, and ERT datasets collected over the highest priority depression; intrusive investigations discovered a hand-dug pit containing animal bones. This approach is suggested for Latin American searches.     

Forensic or Archaeological Issue: Is Chemical Analysis of Dental Restorations Helpful in Assessing Time Since Death and Identification of Skeletonized Human Remains?

In 2011, small mass grave with completely skeletonized remains was discovered in Belgrade suburb. An eyewitness claimed that skeletons belonged to German soldiers killed in WWII. Anthropologists were engaged to investigate whether the skeletal remains correspond to the indicated German group or represent more recent case requiring court trial. Numerous dental restorations were noticed. Owing to the fact that different dental materials were used in dental practice at certain times, the aim of this study was to explore whether analysis of dental restorations could help in identification and estimation of time since death. Inductively coupled plasma optical emission spectrometry revealed that dental fillings corresponded to copper amalgam, conventional silver amalgam, silicophosphate cement, and zinc phosphate cement. Chemical results combined with anthropological and historical facts suggest that the individuals lived before the 1960s in country with well‐developed dental service at that time. Therefore, chemical analysis of dental fillings was useful to distinguish between skeletal remains that are too old to be of forensic interest and the remains relevant to legal investigations.     

Policing labor: the power of private security guards to search workers in Brazil

The losses caused by worker theft is one of the most concerning security problems for corporations. Private policing of the workplace is central to cutting down on such losses and keeping up profits. One of the most frequently used methods in such policing is searching workers. Despite the importance of searches and their potential for intrusion into individuals’ right to privacy, the normative bases for and limits to the use of this power have so far been little studied. The aim of this paper is to analyze the legal foundations and limits imposed by the Brazilian State so that private security guards can conduct searches in the workplace. The analysis is based on a qualitative study of Brazilian labor law and a qualitative/quantitative study of 376 judicial decisions on searches collected randomly in two Brazilian states between 2010 and 2013. The data shows that searches can be conducted in the workplace based on the employer’s right to manage production and protect their property. It also indicates the existence of relatively flexible limits to searches. Only a minority of the courts impose restrictions on searches similar to those set for police officers. Most judges allow more extensive searches than those permitted within the scope of public justice systems. The consequences of these findings are discussed.     

Possible express identification of human remains in case of their intense destruction after exposure to physical factors

The problem of identification of human remains is still one of the most difficult and pressing problems of forensic medicine. Such identification is particularly difficult in cases of intense destruction caused by exposure to physical factors (explosion, contusion, fire, compression, etc.). Approaches to identification in such cases are less available and differ essentially from traditional approaches used, for example, in cases when the remains are exposed to natural long-acting factors. This "white spot" is attempted to be liquidated by investigating aircraft accidents with grave destructive results. The potentialities of express identification of human remains in such cases are shown and a complex of characteristic signs which can serve as the landmarks are distinguished. The authors emphasize the strict adherence to certain regulations when working at the site of technogenic disasters and the hazards of disordering the process of identification in case these regulations are neglected.     

Modelling the buried human body environment in upland climes using three contrasting field sites

Despite an increasing literature on the decomposition of human remains, whether buried or exposed, it is important to recognise the role of specific microenvironments which can either trigger or delay the rate of decomposition. Recent casework in Northern England involving buried and partially buried human remains has demonstrated a need for a more detailed understanding of the effect of contrasting site conditions on cadaver decomposition and on the microenvironment created within the grave itself. Pigs (Sus scrofa) were used as body analogues in three inter-related taphonomy experiments to examine differential decomposition of buried human remains. They were buried at three contrasting field sites (pasture, moorland, and deciduous woodland) within a 15 km radius of the University of Bradford, West Yorkshire, UK. Changes to the buried body and the effect of these changes on hair and associated death-scene textile materials were monitored as was the microenvironment of the grave. At recovery, 6, 12 and 24 months post-burial, the extent of soft tissue decomposition was recorded and samples of fat and soil were collected for gas chromatography mass spectrometry (GCMS) analysis. The results of these studies demonstrated that (1) soil conditions at these three burial sites has a marked effect on the condition of the buried body but even within a single site variation can occur; (2) the process of soft tissue decomposition modifies the localised burial microenvironment in terms of microbiological load, pH, moisture and changes in redox status. These observations have widespread application for the investigation of clandestine burial and time since deposition, and in understanding changes within the burial microenvironment that may impact on biomaterials such as hair and other associated death scene materials.     

Use of thermal drone in detection and assessment of larval mass temperature in decomposed rabbit carcasses

Manual ground searches and cadaver dogs are traditional methods for locating remains, but they can be time- and resource-intensive, resulting in the decomposition of bodies and delay in victim identification. Therefore, thermal imaging has been proposed as a potentially useful tool for detecting remains based on their temperature. This study investigated the potential of a novel search technique of thermal drones to detect surface remains through the detection of maggot mass temperatures. Two trials were carried out at Selangor, Malaysia, each utilizing 12 healthy male Oryctolagus cuniculus European white rabbits and DJI Matrice 300 RTK drone China, equipped with a thermal camera; Zenmuse H20T to record the thermal imaging footage of the carcasses at various heights (15, 30, 60–100 m) for 14 days for each trial. Our results demonstrated that the larval masses and corresponding heat emissions were at their largest during the active decay stage; therefore, all the carcasses were observable in thermal images on day 5 and remained until day 7. Statistical analyses showed that (1) no statistically significant differences in thermal images between clothed and unclothed subjects (p > 0.05); (2) 15 m above ground level was proven to be the optimal height, as it showed the greatest contrast between the carcass heat signature and the background (p < 0.005). Our data suggested the potential window of detection of thermal signatures was detectable up to 7 days post-deposition. This could be an important guideline for the search and recovery teams for operational implementation in this tropical region.     

The Application of Remote Sensing for Detecting Mass Graves: An Experimental Animal Case Study from Costa Rica*

Abstract: Detection of mass graves utilizing the hyperspectral information in airborne or satellite imagery is an untested application of remote sensing technology. We examined the in situ spectral reflectance of an experimental animal mass grave in a tropical moist forest environment and compared it to an identically constructed false grave which was refilled with soil, but contained no cattle carcasses over the course of a 16‐month period. The separability of the in situ reflectance spectra was examined with a combination of feature selection and five different nonparametric pattern classifiers. We also scaled up the analysis to examine the spectral signature of the same experimental mass grave from an air‐borne hyperspectral image collected 1 month following burial. Our results indicate that at both scales (in situ and airborne), the experimental grave had a spectral signature that was distinct and therefore detectable from the false grave. In addition, we observed that vegetation regeneration was severely inhibited over the mass grave containing cattle carcasses for up to a period of 16 months. This experimental study has demonstrated the real utility of airborne hyperspectral imagery for the detection of a relatively small mass grave (5 m²) within a specific climatic zone. Other climatic zones will require similar actualistic modeling studies, but it is clear that the applications of this technology provide the international community with both an early detection tool and a tool for ongoing monitoring.     

Mites (Acari) as a Relevant Tool in Trace Evidence and Postmortem Analyses of Buried Corpses

This report interprets the presence of mite species in three clandestine graves in Europe, evaluating their potential use as trace evidence or markers. Grave 1 (Sweden): Two mite species Rhizoglyphus robini Claparède, 1869 and Parasitus loricatus (Wankel, 1861) were recovered from the surface of a body buried in a shallow grave in an area surrounded by trees, in close vicinity to house gardens. Grave 2 (Germany): Phoretic deutonymphs of Gamasodes spiniger (Trägårdh, 1910) were attached to an adult fly (Diptera: Sphaeroceridae) found within a shallow grave containing two human bodies covered in soil and dung. Grave 3 (France): P. loricatus were recovered from the soil around a body buried in a deep grave (80 cm under). In graves 1 and 3 both corpses were undergoing advanced decay and skeletization, the locations match with the subterranean habit of P. loricatus, highlighting the value of this species as a marker of graves or burials in soil and during late decomposition. R. robini is a soil mite that feeds on decayed roots and bulbs; this mite species confirms the location of the corpse within top soil, agreeing with a more specific type of superficial burial, a shallow grave. In case 2, the presence of both coprophiles, the mite G. spiniger and the carrier fly confirm association of remains with dung or animal feces. The three mite species are reported for the first time in human graves. There are no previous records of R. robini from Sweden.     

The Use of an Alternate Light Source for Detecting Bones Underwater

When searching underwater crime scenes or disaster scenes for fragmentary human remains, it may be advantageous for forensic divers to be able to detect the presence of bones and teeth among other marine materials (such as shells and rocks). In terrestrial environments, this can typically be accomplished by visual and instrumental methods, but underwater conditions make it difficult to employ detection and sorting techniques in these environments. This study investigates fluorescence of bones and teeth and other marine materials using a submersible alternate light source (ALS) and concludes that an ALS can be a useful tool for detecting bones and teeth in underwater searches as well in terrestrial searches and laboratory environments. The results could impact the methods and equipment used by forensic divers and forensic anthropologists when searching for skeletal remains, potentially increasing the quantity and efficiency of forensic evidence recovered.     

Planning the archaeological recovery of evidence from recent mass graves

Mass graves commonly contain hundreds of putrefying bodies, which bear evidence of torture and extrajudicial execution. These require careful excavation using archaeological techniques to recover the bodies for identification and to obtain associated evidence which document human rights abuses. In order to derive forensically defensible conclusions, exhumation of a mass grave may take weeks or months. Specialized protective suits and breathing apparatus will permit the investigating team to take the time required to retrieve even subtle evidence from repellent remains. Strategies for sampling tissues and bodies which reduce the magnitude of the recovery operation are described.     

Assessing the Use of Profiling in Searches by Law Enforcement Personnel

This article considers statistical means of evaluating profiling in searches of individuals by law enforcement agencies. It reviews examples of inappropriate methods that have been used to date. A relatively recent, more appropriate, and simple method is elaborated and its usefulness documented with data from Maryland State Police highway stops and searches. The method evaluates profiling for specified groups of interest by comparing the relative magnitudes of contraband find rates among those stopped and searched of each group. When find rates are approximately the same across groups, then profiling used in making the stops and searches is deemed effective and nondiscriminatory. With an increasing number of jurisdictions mandated to collect data on stops and searches, it is important that appropriate methods be used in their analyses so correct public policy conclusions can be drawn.     

Skeletal evidence of the ethnic cleansing actions in the Free City of Danzig (1939-1942) based on the KL Stutthof victims analysis

In the early days of World War II, many of the prominent and influential people of Polish nationality from the Free City of Danzig were arrested by the Germans and sent to the nearby concentration camp KL Stutthof. Nearly a hundred of them died within the next seven months upon their arrival, and were buried in a clandestine mass grave in a nearby forest. However, the exact nature of their death is unknown, as it is unclear what the attitude of the aggressors was toward the victims. We do not know whether there was only one executioner or there were several assassins, nor if the killing methodology was consistent with the other state-regulated executions.The studied material represents the commingled remains of a minimum thirty-four people, possibly all male, aged from under eighteen to over sixty at the time of death. Perimortem traumatic lesions are shown mainly on the skull bones. We asked whether the perimortem trauma lesions visible on the victims’ skeletons could be informative on the cause and manner of their death.Our results show the prevalence of the perimortem trauma inflicted by a blunt object are on the parietal bones above the Hat Brim Line (HBL), which is commonly associated with a violent attack. The gunshot trauma was usually localized on the occipital bone or posterior parietal, which could indicate a shot to the back of the head, and this was commonly encountered during executions. No signs of defensive injuries can be explained either by restraining of the hands or by a surprise attack. The abundance and variability of the trauma type can be evident of multiple assailants. Moreover, the multiple impact points detected on several crania prove unnecessary overkill and brutality, which reflects the personal attitudes of the executioners towards the victims.     

The Effect of Time on Bone Fluorescence: Implications for Using Alternate Light Sources to Search for Skeletal Remains

Bones fluoresce when exposed to certain wavelengths of shortwave light, and this property can be useful in locating and sorting skeletal remains in forensic contexts. The proteins in bone collagen are largely responsible for its fluorescent properties, but these proteins degrade and denature over time. This study examined the fluorescence of bones from four temporal groups (recent, semi‐recent, ancient, and historic) ranging from 0 to 1064 years before present. Specimens were photographed under 490 nm wavelength light, and fluorescence was quantified by converting intensity to a gray scale value based on the RGB color model using ImageJ^® software. Significant (p < 0.05) differences were found in mean fluorescence between all four temporal groups, and a 0.324 coefficient of correlation indicates a significant (inverse) relationship between fluorescence and time. Bone fluorescence decreases with time, but some fluorescence is retained even in older samples. Fluorescence can therefore be reliably used in many modern skeletal remains searches.     

The use of cadaver dogs in locating scattered, scavenged human remains: preliminary field test results

Specially trained air scent detection canines (Canis familiaris) are commonly used by law enforcement to detect narcotics, explosives or contraband, and by fire investigators to detect the presence of accelerants. Dogs are also used by police, military, and civilian groups to locate lost or missing persons, as well as victims of natural or mass disasters. A further subspecialty is "cadaver" searching, or the use of canines to locate buried or concealed human remains. Recent forensic investigations in central Alberta demonstrated that the use of cadaver dogs could be expanded to include locating partial, scattered human remains dispersed by repeated animal scavenging. Eight dog-and-handler teams participated in a two-month training program using human and animal remains in various stages of decay as scent sources. Ten blind field tests were then conducted which simulated actual search conditions. Recovery rates ranged between 57% and 100%, indicating that properly trained cadaver dogs can make significant contributions in the location and recovery of scattered human remains.