Dissertation committee:
Μωραΐτης Κωνσταντίνος, Αναπληρωτής Καθηγητής, Ιατρική, ΕΚΠΑ
Σταυρούλα Παπαδόδημα, Αναπληρώτρια Καθηγήτρια, Ιατρική, ΕΚΠΑ
Χάιδω Σπηλιοπούλου, Καθηγήτρια, Ιατρική, ΕΚΠΑ
Δημήτριος Βλαχοδημητρόπουλος, Αναπληρωτής Καθηγητής, Ιατρική, ΕΚΠΑ
Νικόλαος Γούτας, Αναπληρωτής Καθηγητής, Ιατρική, ΕΚΠΑ
Χρυσόστομος-Αλέξιος Κελέκης, Αναπληρωτής Καθηγητής, Ιατρική, ΕΚΠΑ
Αθανάσιος Σφέτσος, Δρ Ερευνητής Β΄, ΕΚΕΦΕ Δημόκριτος
Summary:
This study investigated the characteristics of gunshot wounds in the human body depending on the type of bullet used.
In wound ballistics research, there is a relationship between the construction and properties of a bullet and the resultant injuries when a projectile penetrates or perforates the soft tissues of the human body. The bullet path in the human body following skin perforation as well as the damaging effects cannot always be predictable as they depend on various factors, such as the bullet’s impact velocity, its construction and the tissue types that the bullet encounters.
A part of this study includes a survey about the distribution of firearms calibers used in offences against human life in Greece. The data that were collected cover the last twenty years from 1995 to 2014. This data was only from crimes which involved firearms used against human life, such as homicides, attempted homicides, robberies, and terrorist acts. The recovered evidence consisted of cartridge cases, bullets, bullet fragments and, in some cases, firearms. The used firearms were classified into five different categories: pistols, revolvers, sub-machine guns, rifles and shotguns. According to the results, incidents in which a person was actually struck by a projectile accounted for 66,6% of the total number of all cases. Besides, 70% of the firearms used in the homicides for the last twenty years were handguns. Furthermore, from this 20-year study, the leading contender in the caliber category is the 9mm Parabellum (33%) for firearms crimes in Greece. The results of this survey show the distribution of crimes in Greece according to the caliber of the type of firearm used.
Another part of this study refers to using CT technology and studying virtual ‘slices’ of specific areas on scanned human bodies. That allowed the evaluation of density of skin, subcutaneous tissue, muscle, vital organs, and bones. Density data taken from Hounsfield units were converted in g/ml by using the appropriate software. The biophysical analysis in wound ballistics provides another application of CT technology, which is commonly used for diagnostic and therapeutic purposes in various medical disciplines. Data were collected by using DICOM images from people of different age, sex and weight underwent CT examinations on a Philips Brilliance 64-slice CT scanner installed at the 2nd Department of Radiology in University General Hospital ATTIKON, in Athens, Greece. The ability of taking measurements of density from the layers of human bodies gives the opportunity to calculate values of density on average, according to which ballistic gelatine can be produced for more pragmatic and accurate results.
Furthermore, eight real cases of firearm-related deaths were examined. For all of them, autopsies took place at the Department of Forensic Medicine and Toxicology, School of Medicine of National and Kapodistrian University of Athens. In co-operation with the forensic pathologist data were collected about the entry and exit wounds, the wound paths and the damage produced in the body. In all autopsies the usual procedure was followed and any further examination occurred just in observation of the victim as collecting data from the wounds.
Finally, experimental shootings into materials similar to various areas and organs of the human body are necessary in any effort to evaluate the behavior of a bullet in wound ballistics research. Specifically, ballistic soap and ballistic gelatin, which can be produced under specific conditions allow for one to document and record the simulated path that a bullet may take in the human body. Projectiles in caliber of 9mm Parabellum were used mainly for the experiments. Analysis of wound paths in these simulant materials through CT scanning provided an opportunity to observe and calculate the characteristics of wound channels as they relate to specific projectiles and impact velocities, and also to compare the effectiveness of the different bullet types that were used. Through CT technology the density of these scanned blocks could be recorded. Furthermore, using CT technology and studying the scanned blocks allowed the evaluation of the data derived from the bullet's path through each block. The analysis of the CT scanned blocks after CT post-processing provided the ability to accurately measure the characteristics of the created wound channels after each shot. Tissue simulant materials, such as ballistic soap and ballistic gelatin reflect the transfer of a bullet’s kinetic energy after its perforation and movement into these media. During deceleration of the projectile for a very short time (msec), the medium is stretched perpendicularly to the projectile’s course forming the ‘temporary cavity’. The results also show that a highly accurate numerical analysis of the temporary cavities produced by experimental shootings is only possible using the 3D digital imaging capabilities of CT scanning in ballistic soap. With ballistic gelatin, only the permanent wound track can be observed and measured with accuracy through CT technology. However, a properly prepared 10% (w/w) ballistic gelatin at 4oC has become the recognized standard as a soft tissue simulant. The terminal ballistic behavior and penetration of 9mm Parabellum bullets in ballistic gelatin very closely mimic what happens in living muscle tissue.
Wound documentation during forensic autopsy and any subsequent efforts to reconstruct a shooting can become crucial. This information can aid in understanding the injurious effects on the human body by the type of bullet associated with the victim’s gunshot wound(s). Such an understanding can be derived through experimental shots into a suitable tissue simulant with the ammunition used in the shooting.
Keywords:
Wound ballistics, Firearms, Bullet, Human body, Gelatin, Experimental shootings, Computed tomography
