Gunshot to the pelvis – Experimental ballistics and forensic radiology

Virtual Trauma Analysis of the Nineteenth-Century Severed Head of the Greek Outlaw Stavrou

Human remains have been displayed in museums in Europe since many centuries for historical, cultural, and educational reasons. Of particular interest are skeletal remains and body parts that have suffered violent deaths and such remains often feature in Criminology Museums. Despite the well-acknowledged value of human remains in medical education, bioarchaeology, and research, the display of human remains still raises ethical considerations ranging in severity depending on the cultural substrate and legal framework of each country. Recent developments in medical imaging and visualisation are offering an alternative way. Taking into account the emerging issues regarding exhibition and handling of human remains, this research project aims to use virtual methods to reconstruct the circumstances of the death of a nineteenth-century outlaw comprising one of the human exhibits at the Criminology Museum of Athens in Greece.For the purpose of the project, the severed head of the outlaw Stavrou was CT scanned, and the data were used to reconstruct and to evaluate the ballistic trauma sustained at the time of his death. From the scans, it was possible to determine the minimum number of shots, entrance and exit wounds, approximate calibre of the bullets, approximate distance from which they were fired, and general velocity of the round.Shots are fired from the lateral left and backside of the head and bullets exited from the right frontal and temporal area causing extensive damage to the right craniofacial region. The direction of the shots coming from the back and left suggests that Stavrou was more likely ambushed by gendarmerie squads and not shot in a fair fight which would have caused entry wounds in the anterior surface of the body. This is in agreement with historical evidence that placed him in gunfire with his fellow gang member Karapanos against a government squad. On the other hand, the possibility of being captured alive and executed cannot be rejected based only on wound ballistics.This work would be excellent supplementary material to the actual human exhibit for the accurate presentation of Stavrou's history at the Criminology Museum. In addition, it would allow the virtual exhibition of the material for historical and teaching purposes to museums and universities anywhere in Greece and along the globe, thus overcoming the obstacles of moving the actual remains.

Ten years of molecular ballistics-a review and a field guide

Molecular ballistics combines molecular biological, forensic ballistic, and wound ballistic insights and approaches in the description, collection, objective investigation, and contextualization of the complex patterns of biological evidence that are generated by gunshots at biological targets. Setting out in 2010 with two seminal publications proving the principle that DNA from backspatter collected from inside surfaces of firearms can be retreived and successfully be analyzed, molecular ballistics covered a lot of ground until today. In this review, 10 years later, we begin with a comprehensive description and brief history of the field and lay out its intersections with other forensic disciplines like wound ballistics, forensic molecular biology, blood pattern analysis, and crime scene investigation. In an application guide section, we aim to raise consciousness to backspatter traces and the inside surfaces of firearms as sources of forensic evidence. Covering crime scene practical as well as forensic genetic aspects, we introduce operational requirements and lay out possible procedures, including forensic RNA analysis, when searching for, collecting, analyzing, and contextualizing such trace material. We discuss the intricacies and rationales of ballistic model building, employing different tissue, skin, and bone simulants and the advantages of the “triple-contrast” method in molecular ballistics and give advice on how to stage experimental shootings in molecular ballistic research. Finally, we take a look at future applications and prospects of molecular ballistics.

Evaluation of the backspatter generation and wound profiles of an anatomically correct skull model for molecular ballistics

Molecular ballistics connects the molecular genetic analysis of biological traces with the wounding events and complex forensic traces investigated in terminal ballistics. Backspatter, which originates from a projectile hitting a biological target when blood and/or tissue is propelled back into the direction of the gun, is of particular interest; those traces can consolidate and persist on the outer and inner surfaces of firearms and serve as evidence in criminal investigations. Herein, we are the first to present an anatomically correct head model for molecular ballistic research based on a polyurethane skull replica enclosing tissue-simulating sponge material that is doped with "triple-contrast" mixture (EDTA-blood, acrylic paint, and an x-ray contrast agent). Ten percent ballistic gelatin was used as brain simulant. We conducted contact and intermediate-range shots with a Glock 19 pistol (9 mm Luger), a pump-action shotgun (12/70 slugs), and blank cartridge handguns. Each shot was documented by a high-speed camera at 35,000 fps. Apart from the blank cartridge guns, all gunshots penetrated the skull model and created backspatter, which was recovered from the distal part of the barrels and analyzed. The pistol contact shots and one of three shotgun shots yielded full STR profiles. While the shotgun slugs destroyed the skulls, the remaining models could be used for radiological and optical fracture and wound channel evaluation. Known backspatter mechanisms and their respective timing could be confirmed visually by video analysis. Our complete model setup proved to be well applicable to molecular ballistic research as well as wound channel and fracture pattern investigation.

Individual synthetic head models in wound ballistics - A feasibility study based on real cases

Synthetic models, also called "surrogates", are commonly used in wound ballistics in order to simulate human tissues. Despite several surrogates are worldwide accepted and used; some of them have not been yet fully validated and their limits for forensic reconstructions have not been deeply investigated yet. In this work we present a homicide/suicide case involving three gunshots to the head with bullets retained in the skull or beneath the scalp. Reconstruction of these cases was performed preparing three individual synthetic head models based on post-mortem computed tomography (PMCT) measurements. Ballistic soap, polyurethane plates and 10% ballistic gelatine at 4°C were used as simulants in individually adapted thickness. Ballistic tests were performed using the questioned firearm and ammunition type. The damages on the synthetic models have been compared to the findings in PMCT and autopsy of the victims. Although the results highlighted general similarities in terms of injury characteristics, some of the experimental shots overpenetrated. Furthermore, the bullets recovered in the synthetic models did not show the same quality of deformations as the questioned bullets. This lack of bullet deformation in the synthetic models might be mainly attributed to the physical difference between real bones and polyurethane surrogate.

Ballistic impacts on an anatomically correct synthetic skull with a surrogate skin/soft tissue layer

The aim of this work was to further develop a synthetic model of ballistic head injury by the addition of skin and soft tissue layers to an anatomically correct polyurethane skull filled with gelatine 10% by mass. Six head models were impacted with 7.62 x 39 mm full metal jacket mild steel core (FMJ MSC) bullets with a mean velocity of 652 m/s. The impact events were filmed with high-speed cameras. The models were imaged pre- and post-impact using computed tomography. The models were assessed post impact by two experienced Home Office pathologists and the images assessed by an experienced military radiologist. The findings were scored against real injuries. The entry wounds, exit wounds and fracture patterns were scored positively, but the synthetic skin and soft tissue layer was felt to be too extendable. Further work is ongoing to address this.