Investigation into the merits of infrared imaging in the investigation of tattoos postmortem

Infrared imaging has a history of use in the forensic examination of artwork and documents and is investigated here for its wider use in the detection of tattoos on the human body postmortem. Infrared photographic and reflectographic techniques were tested on 18 living individuals, displaying a total of 30 tattoos. It was observed that neither age, sex, age of the tattoo, nor, most significantly, skin color affected the ability to image the tattoos using infrared imaging techniques. Second, a piglet carcass was tattooed and the impact of the decomposition process on the visibility of the tattoos assessed. Changes were recorded for 17 days and decomposition included partial mummification and skin discoloration. Crucially, the discoloration was recorded as greatly affecting the image quality using conventional photography, but was insignificant to the infrared recording of these tattoos. It was concluded that infrared reflectography was beneficial in the investigation into tattoos postmortem.     

Über Methoden zur Darstellung von latenten Fingerabdrücken auf der menschlichen Haut

Five methods are described for the detection of latent fingerprints on human skin: the X-ray method, the application of laser radiation, the iodine-silver plate transfer method, development with iron powder and Dakty-foil, as well as the photographic paper lift technique. Experiences with the application of these methods in forensic investigations are reported, and impeding factors are outlined. The simpler methods (the detection of such prints with iron powder and Dakty-foil as well as the photographic paper lift technique) are to be preferred for the investigation at the scene of the crime.     

Skull and photographic superimposition: a new approach using a second party's interpupil distance to extrapolate the magnification factor

The photographic superimposition technique requires an antemortem photograph to be enlarged to life size and the skull to be photographed from the same angle as the antemortem photograph. This paper describes how the magnification factor can be extrapolated by measuring the true interpupil distance of a second person and the photographic interpupil distance of the suspect and the second party. A closed-circuit television (CCTV) system is used to determine quickly the skull photographic angle. We believe these techniques are viable and easy to perform.     

指甲伤的类型与形成机制研究

目的探讨人体体表指甲伤的分型与形成机制。方法收集法医实际检案资料51例指甲伤434处,借助放大镜对各处伤进行形态特征观察、归类整理。结果指甲伤可分为条状抓擦伤、片状压擦伤和弧状压挫伤/创3种基本类型,分别有168处、153处和113处,其形态特征改变主要与成伤指甲的结构,作用力的大小、方向、作用时间,伤处皮肤的松驰度、Langer线走向,伤后经过时间等因素有关。结论指甲伤的类型和成份机制判断对加害人意图的分析和案件定性有重要作用。     

Cigarette burns in forensic medicine

Skin lesions suspected to have been caused by a burning cigarette require thorough diagnostic evaluation as to the mode of infliction. Accidental cigarette burns must be differentiated from injuries due to self-infliction or maltreatment. The typical categories are presented on the basis of the literature and exemplary cases from the authors' own study material. An intentional infliction must be taken into consideration when a body region is involved which does not normally come into contact with a cigarette by chance. Full thickness burns from glowing cigarettes require an exposure time of more than 1s. One should also keep in mind the possibility of confusion with local skin infections or thermal effects by traditional medical practices (e.g. moxibustion). In unclear cases, repeated inspection of the lesion is recommended in order to facilitate its classification as to causation and age. The courses of healing in first- to third-degree cigarette burns are demonstrated by means of continuous photographic documentation. The discussion deals with different kinds of accidental and intentional cigarette burns, e.g. in drug addicts, psychiatric patients, victims of child abuse, maltreatment and torture, but also in persons feigning a criminal offence.     

Matching the lost skin of a homicide suspect

A case of matching a fragment of lost skin to a homicidal assailant's thumb is reported. The methods used included physical and photographic matching of corresponding configuration and skin ridges, serological blood grouping and enzymes typing. The conclusiveness of such a matching approach is self-evident.     

Inter-/Intra-observer Reliability of Hand Assessment Using Skin Detail: A Count-based Method

Skin detail of the hand is used in photographic comparisons, yet its reliability has not been evaluated. This study examines a count-based method for documenting skin features. In Part I, 14 individuals counted skin features on 40 color images of the hand, three of which were repeated. An average correlation value of 0.557 was obtained for interobserver assessment; values ranged from 0.545 to 0.832 for intra-observer assessment. The variation in correlation values for hands suggests that there are certain distinguishing characteristics that increase reliability. In Part II, 17 examiners assessed 20 nonrepeated grayscale images of hands by circling skin features. An average correlation value of 0.674 was obtained, but visual assessment of examiner markings suggested some examiners grouped features whereas others viewed them individually. The results suggest further research is warranted, some hands may be more suitable for comparisons, and a standardized method for examining skin features is needed.     

Forensic medical examination of abrasions in the study of mummified tissues in experiment

Morphological and biophysical characteristics of abrasions and intact skin were studied during the process of their mummification at temperatures from 40 to 70 degrees C. The time after which the injuries become undetectable because color of the skin and injuries coincides, was determined. Changes in configuration and area of abrasions while drying are described. The rate of mummification and duration of the latter were established by dielectric indices of abrasions and skin at 10 cm wave length.     

Classification of skin injuries inflicted by the teeth of the carnivorous animals

The current approaches to the classification of skin injuries inflicted by the teeth of the carnivores on the human body are discussed. The new morphological classification is proposed taking into consideration the current views of the mechanisms underlying the formation of tooth marks on the integumental tissues of the victims of attacks by carnivorous animals. Morphological characteristics of skin injuries are briefly described in the framework of the new classification.     

Pelvic age estimation using actual specimens and remote images

Age estimates of the auricular surface (sacro-iliac joint) of the ilium taken from bony specimens, 35 mm slides, and digital images were compared for 29 intact specimens from archaeological contexts. Results demonstrate that age estimates from all photographic and digital images may result in significantly differing estimates of age than those from bony specimens. Of the imaging techniques, 35 mm slides provided estimates most similar to those from bony specimens. Digital images provided age estimates that varied more from bony specimens. In general, photographic and digital images may offer researchers a way of documenting age information that would otherwise be unavailable or delayed. Yet, caution should be used when age estimates are derived solely from images rather than from bony specimens.     

Singular case of shooting a football fan with a signal rocket

The authors present a very rare case of fatal injuries resulting from shooting a parachute signal rocket with a hand operated launcher of signal pistol kind by pseudo-football fans. A 16-year-old football fan sustained extensive thermal burn of his lower extremities and abdomen, lacerated wound of his left thigh with a deep signal rocket-shot canal which caused injuries in subcutaneous tissue, fascia and both medial and posterior muscles of the thigh as well as injured both femoral vein and artery with subsequent hemorrhagic, burn and traumatic shocks. In spite of specialistic surgical treatment, the victim was not rescued. Analysis of medical documentation and our autopsy results were supplemented with an expert's opinion on physicochemical examinations supported by photographic documentation.     

数字图像处理在尸体面貌辨认照相中的应用

本文就数字图像处理技术在尸体面貌辨认照相中对尸体面部肤色的调整，伤痕、残缺部位的修复和在尸体面貌辨认相片拼接中的应用以及处理后的尸体面貌辨认相片在公安刑侦系统内部局域网上的应用作了阐述。     

Death by lightning

Deaths from lightning injuries are infrequent, amounting to 0.2-0.8 per million people per year, and are associated with climatologic conditions. The victims are mostly young, active people who are struck during various outdoor activities during the summer months. Even though many people can be struck by the same bolt of lightning, multiple casualties are uncommon. Among the fatalities, various types of skin burns are regularly present, often at an entry site on or near the head, and at an inferiorly located exit site. These skin injuries often consist of superficial burns and singed hair; deep burns and charring are uncommon. Arborescent skin marks seem to occur less frequently. Internal findings at autopsy are nonspecific.     

A preliminary study of skin electrical injury with computerized image analysis

This paper reports the application of computerized image analysis to a quantitative study of skin electrical injury in order to provide an objective and quantitative standard for identifying the electrical mark. The differences between antemortem and postmortem electrical injuries were also studied. In normal and electrically-injured human skin, the long/short axes ratio of nuclei were measured. The mean of epithelial basal cells was 1.4344 and 5.9325, respectively, the mean of hair follicle cells was 1.6193 and 4.5988, respectively, and the mean of capillary endothelial cells was 4.0229 and 4.3593, respectively. In rat specimens, the long/short axes ratio of nuclei of normal skin, at 15 and 5 min ante-mortem and at 5 min postmortem injury, the mean epithelial basal cells was 1.4124, 4.5417, 5.2282 and 5.0447, respectively. The mean of hair follicle cells was 1.4140, 4.4863, 4.1146 and 4.4522, respectively, while the mean of capillary endothelial cells was 2.8398, 3.7514, 3.6159 and 3.6977, respectively. The results indicate that the differences between electrical injuries and normal skin with respect to the ratios of long/short axes of the epithelial basal cell nuclei and hair follicle cell nuclei are of remarkable significance. On the other hand, no significant difference could be found between antemortem and postmortem injuries, nor between electrical injury and normal skin, concerning the long/short axes ratios of capillary endothelial cell nuclei. This result provides a preliminary objective standard for the changes of electrical skin injury.     

电警棍致皮肤损伤的实验研究

本研究系用电警棍电击实验动物（猪），观察电击部位的皮肤喷涂金属显色剂后的颜色改变、组织学改变及金属含量的改变。结果表明，电警棍电击机体，不仅可致皮肤产生肉眼可见的损伤，而且可致皮肤细胞产生轻微的极化现象和皮肤金属化，这种金属化可通过金属显色剂喷涂和原子吸收分光光度计检测出来．本实验为电警棍电击伤的定性分析、检材的提取与处理提供了比较好的方法，有利于判定案件的性质和确定电警棍的种类。     

Physical forms of contemporary small-arms propellants and their forensic value

Intermediate gunshot wounds typically produce powder tattooing and/or stippling of the skin. The size and density of such powder-induced injuries around an entry wound are used to estimate the separation distance between the muzzle of the responsible firearm and the entry site through test firings at selected muzzle-to-target distances, with ammunition comparable to the injury-producing round and the evidence firearm. The foregoing is well known to forensic pathologists who document and describe such powder patterns in gunshot victims and firearm examiners who customarily produce the test-fired powder patterns for subsequent range-of-fire determinations. Less known, particularly to pathologists, is the considerable variety in forms of modern nitrocellulose propellants, their effects on powder-induced injuries to human skin, and the value of these varied physical forms in the reconstruction of shooting incidents. These factors are the subject of this article.     

Morphological characteristics of gunshot wounds of liver and spleen

Stellate wounds are to be expected in gunshot injuries to the liver and spleen. As to their configuration, they resemble the skin breaks in an absolute close-range shot. The exit wound is larger than the entry wound. The genesis and utility of such injuries for reconstruction of the shot direction are discussed with reference to seven gunshot mortalities. Stellate wounds could also be achieved by shooting at isolated cadaver organs. The experimentally produced gunshot wounds differed from those produced in vivo in that the entry and exit wounds were equally large.     

Is the exploding powder gas of the propellant from blank cartridges sterile?

Shots from blank weapons loaded with blank cartridges, when fired from close range or as a contact shot, almost always cause the skin to burst open and lead to injuries to structures below the surface. Subsequently, wound infections are often observed. In addition to the introduction of skin germs, the possibility exists that contaminated propellants may enter into consideration as a source of infection. Using step-by-step experimental procedures we were able to demonstrate that: 1. Blank cartridge propellants were almost always contaminated with Bacillus cereus (nitrocellulose powder more so than black powder); 2. When the shot is fired numerous bacteria survive and are forced out with the gunsmoke from the weapon and thus find their way into the wound. In principle, blank cartridge propellant thus exhibits as much potential for wound infection as the skin germs. Clearly, the species B. cereus is prominent in this context. For open injuries even with ‘harmless’ blank weapons, an antibiotic prophylaxis should always be administered.     

Localization and quantification of histamine in injured skin as parameters for the timing of wounds.

Localization and estimation of the histamine (HA) content in skin wound edges in 86 Sprague-Dawley rats and three cases of human injuries were carried out by a microfluorimetric method specific for this amine which forms a complex with o-phthalaldehyde (OPT). Distribution and density of the mast cells in the same areas were observed at the same time by toluidine blue stain. In all skin specimens with antemortem wounds, both the epidermis and upper dermis exhibit extracellular yellowish fluorescence of the HA-OPT complex. The fluorescent zone spreads in the wound edges with the lapse of time in vital injuries. The HA content increases gradually up to 30 min and then the yellow histamine fluorescence in areas 0-200 microns from the wound edge decreases. None of these features can be observed in normal skin and postmortem-injured skin. Mast cell degranulation can be demonstrated in all antemortem-injured skin. No statistical relationship exists between the number of mast cells and the HA-OPT fluorescence in either ante- or postmortem-injured groups. This study indicates that skin HA microfluorimetry by the OPT method is of practical value for distinguishing ante- from the postmortem wounds and for timing antemortem wounds.     

Optical 3D surface digitizing in forensic medicine: 3D documentation of skin and bone injuries

Photography process reduces a three-dimensional (3D) wound to a two-dimensional level. If there is a need for a high-resolution 3D dataset of an object, it needs to be three-dimensionally scanned. No-contact optical 3D digitizing surface scanners can be used as a powerful tool for wound and injury-causing instrument analysis in trauma cases. The 3D skin wound and a bone injury documentation using the optical scanner Advanced TOpometric Sensor (ATOS II, GOM International, Switzerland) will be demonstrated using two illustrative cases. Using this 3D optical digitizing method the wounds (the virtual 3D computer model of the skin and the bone injuries) and the virtual 3D model of the injury-causing tool are graphically documented in 3D in real-life size and shape and can be rotated in the CAD program on the computer screen. In addition, the virtual 3D models of the bone injuries and tool can now be compared in a 3D CAD program against one another in virtual space, to see if there are matching areas. Further steps in forensic medicine will be a full 3D surface documentation of the human body and all the forensic relevant injuries using optical 3D scanners.