The dynamic development of the muzzle imprint by contact gunshot: high-speed documentation utilizing the "skin-skull-brain model"

Many contact gunshots produce a muzzle imprint in the skin of the victim. Different mechanisms have been discussed in literature as being responsible for the creation of the muzzle imprint. Experimenting upon the synthetic non biological skin-skull-brain model, our goal was to document and study the creation of the muzzle imprint with the aid of high-speed photography. In our experiments, we could document with our high-speed photography (at exposure rates in the range of nanoseconds) the bulging, the pressing against the muzzle, and the splitting of the artificial skin. Furthermore, it was possible to photographically record the back pattern of synthetic tissue particles. And, the soot and gunpowder cavity could be reproduced experimentally. In conclusion the experiments completed with the skin-skull-brain model, using high-speed photography for documentation, show the promising possibilities of experimental ballistics with body models.     

A study of the morphology of gunshot entrance wounds, in connection with their dynamic creation, utilizing the "skin-skull-brain model"

The goal of this study was to document the dynamic effects created within, and the developing mechanisms of a gunshot entrance wound to the skin utilizing high-speed photography and the "skin-skull-brain model". The high-speed photography was taken with an Imacon 468/Hadland-Photonics camera. Full metal jacketed, 9 mm Luger projectiles were fired at the target model from a distance of 10 m. During the evaluation of the "skin-skull-brain model", it was possible to show that injuries inflicted to this model are fully comparable to the morphology of equivalent real gunshot entrance wounds. It has been possible to document and study the dynamic process of the "bullet-skin-interaction" in the gunshot entrance wound. The development of the morphologic terms of the entrance wound are discussed. In combination with high-speed photography, this "skin-skull-brain model" is a perfect tool for the documentation and the study of the dynamic development of gunshot entrance wounds in the skin.     

A "skin-skull-brain model" for the biomechanical reconstruction of blunt forces to the human head

In order to create and study blunt force wound morphology, a "skin-skull-brain model" had to be designed which would make the laboratory reproduction of a blunt force injury to the head possible. During the evaluation of the "skin-skull-brain model", it was possible to show that injuries inflicted to this model are fully comparable to the morphology of equivalent real blunt forces injuries to humans. Utilization of the "skin-skull-brain model" presents some significant advantages: the model is inexpensive, easy to construct, instantly available for use, and eliminates ethics conflicts. The main advantage of such a model is, in comparison with biological substances, the high reproducibility of experimentally inflicted traumas.     

The "inner gunshot residue"--a gunshot entry marker in gunshot of ridged skin]

Gunshot residue below the surface of the skin is typical of a contact gunshot wound. However, in a case of our own, when a taxi-robber was shot by the cab driver through his right hand at a distance of several yards, this finding provoked quite a confusion. Only when experimental shots at thick glabrous skin were performed, it could be established that long range shots led to intraepidermal gunshot deposit too. The explanation of this phenomenon lies in the tenacity of thick skin. Unlike the thin hairy skin, which is punched out by the penetrating projectile, the thicker and more tenacious plantar/palmar epidermis gets displaced radially, the stratum germinativum tears and the projectile casts its gunshot residue in the pouch formed in such a manner. Therefore, intraepidermal gunshot residue is proof of an entrance gunshot wound but not always a sign of contact shot if the wound is located in the palmar or plantar region. It is typically produced by shots at thick skin.     

1例五四式手枪伤人的法医学鉴定及实验研究

五四式手枪伤人案件的法医学鉴定通常较为顺利,但在一些特殊情况下,其射入口和射击距离也引起法医学上的讨论.现将1例五四式手枪致人死亡案例的鉴定过程及所做的相应实验报告如下:     

1例五四式手枪伤人的法医学鉴定及实验研究

五四式手枪伤人案件的法医学鉴定通常较为顺利，但在一些特殊情况下，其射入口和射击距离也引起法医学上的讨论。现将1例五四式手枪致人死亡案例的鉴定过程及所做的相应实验报告如下：案情一司法警察团公务与一群村民发生冲突时击发五四式手枪，致一人死亡。当地法医第2天对死者进行尸表及局部解剖检验认为：死者左臀部创口为射入口；左下腹部创口为射出口，创口周围的点状表皮剥脱为昆虫叮咬所致；射击距离为50cm以远。与调查情况出入较大，遂报上级法医复核鉴定，第3天进行复核检验。复核检验情况：枪击现场为一开阔的土坡上，已遭严重破…     

Forensic applications of sodium rhodizonate and hydrochloric acid: a new histological technique for detection of gunshot residues

Demonstration of the presence of lead residues deriving from gunshot in skin and underlying tissues is essential for the correct forensic analysis of numerous legal cases. Optical microscopy remains the fastest, cheapest diagnostic technique, even though its sensitivity and specificity are poor because of the scarce quantity of histological tissue that can be examined and possible environmental lead pollution. To confirm the presence of lead from gunshot residues, we applied to histological sections of human skin a technique proposed by Owens and George in 1991 for macroscopic detection of lead on the clothing of shooting victims, involving a reaction with sodium rhodizonate and subsequent confirmation by color change on application of HCl. Our results demonstrate the technical possibility of using this macroscopic technique even on histological samples and support the need for further studies on a larger series of cases correlated with the type of ammunition and firing distance.     

Formation of a "crow's foot pattern" in the smoke residue in homicide by forehead gunshot injury

We report a "crowsfoot-like" pattern in the smoke marks around the entrance of a close-range bullet wound in the center of the forehead; the weapon in this homicide was a revolver. This pattern only occurs if the facial muscles that form expression are completely contracted at the moment the shooting occurs and if the victim expects the event. The wrinkles gather around the entrance of the bullet, and this wound pattern may indicate that the shot was expected by the victim and represent a piece of the mosaic that might help clarify the circumstances in a case.     

Metric assessment of the "mastoid triangle" for sex determination: a validation study

Recently, a metric approach to skeletal sex determination was published by Paiva and Segre which is based on the summation of two triangular areas defined by three distinct craniometric landmarks: Porion, Mastoidale, and Asterion. According to the authors, values for the total triangle > or =1447.40 mm(2) are characteristic for male crania, while values < or =1260.36 mm(2) are indicative of female skulls (95% confidence). In order to evaluate the method's validity, two sex- and age-documented samples of different provenience were analyzed (N=197). The results show that while the indicated measurements display significant sex differences, the technique is of little practical meaning where a single individual must be independently classified. It is hypothesized that differences in the expression of sexual dimorphism as well as a population-specific variability of the asterion location undermine the value of the mastoid triangle as a sex determinant.     

A new method for collection and identification of gunshot residues from the hands of shooters

This work presents a novel collection method for gunshot residues (GSR) using a sampling procedure based on ethylenediaminetetraacetic acid (EDTA) solution as a complexing agent on moistened swabs. Detection was via a sector-field inductively coupled plasma mass spectrometry (HRICP-MS). The proposed collection and analytical method allowed detection of antimony (Sb), barium (Ba) and lead (Pb) after .38 shot tests. at detection limits of less than 1 microg L(-1) in four different areas of the hands of volunteers. This paper includes a discussion concerning hand areas near the thumb and forefinger as being more suitable for GSR collection as well as a comparison between differences observed using 2% diluted EDTA. 2% nitric acid solution, and simple deionized water as collecting solutions, proving the superior efficiency of EDTA in GSR recoveries.     

The morphology of the gunshot entry wound

The main signs of inlet gunshot wound inflicted from non-close shot distance are the following: central defect of the tissue, presence of abrasion and rub zones along the margins. During experimental study high variability of these signs was stated and new morphologic characteristics of inlet gunshot wound were detected.     

A "safer mousetrap": the evolution of a model charge for alternative safer design cases

This address is based upon a presentation given at Seton Hall University School of Law's Seventh Annual Health Law Symposium on February 12, 1999.     

枪弹创后置物射出口形态学的实验研究

为建立后置物射出口与射入口的检验鉴定方法，使用国产五四式7．62mm口径手枪及五六式7．62mm口径半自动步枪，以5米的距离射击约克夏种白猪18只，同时以木板、水泥板、玻璃及衣服等作为射出口衬垫物，制成后置物射出口56例，并与对照组12例射出口进行对比观察。结果表明，射出口与后置物距离在3cm以内均可出现创缘伸展轮及皮下出血，且与后置物质地及距离成正比。根据其形态分为典型及非典型两类，并建立了此类射出口的检验方法及其与射入口鉴别的依据，有助于法医在实际检验中对射击方向的判断。     

Bilateral fractures of the coronoid processes: differential diagnosis of intra-oral gunshot trauma and scavenging using a sheep crania model

Approximately half of the skeleton of an adult male (minus the cranium) was found in a forested part of Greater Vancouver, Canada, in August 2000 by the Royal Canadian Mounted Police (RCMP). Authorities ruled the death as suicide. The only compelling signs of perimortem trauma were symmetrically fractured coronoid processes of the mandible, which can be attributed to a gunshot in the mouth. However, the remains had also been scavenged by canids, raising a problem in differential diagnosis. Could canid scavenging produce bilateral fracturing of the mandible indistinguishable from gunshot wounds to the mouth? We found that canid scavengers could not mimic the type of damage to the mandible caused by intra-oral gunshot wounding using a sheep model (n = 20). Bilateral fracturing of the coronoid processes was found to be characteristic of intra-oral gunshot wounding, while canid scavengers typically ignore this region of the mandible.     

Back to first principles: a new model for the regulation of drug promotion

The US Food and Drug Administration''s (‘FDA’ or the ‘Agency’) current regulatory framework for drug promotion, by significantly restricting the ability of drug manufacturers to communicate important, accurate, up-to-date scientific information about their products that is truthful and non-misleading, runs afoul of the First Amendment and actually runs counter to the Agency''s public health mission. Our article proposes a New Model that represents an initial proposal for a modern, sustainable regulatory framework that comprehensively addresses drug promotion while protecting the public health, protecting manufacturers’ First Amendment rights, establishing clear and understandable rules, and maintaining the integrity of the FDA approval process. The New Model would create three categories of manufacturer communications—(1) Scientific Exchange and Other Exempt Communications, (2) Non-Core Communications, and (3) Core Communications—that would be regulated consistent with the First Amendment and according to the strength of the government''s interest in regulating the specific communications included within each category. The New Model should address the FDA''s concerns related to off-label speech while protecting drug manufacturers’ freedom to engage in truthful and non-misleading communications about their products.