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.     

An unusual pattern of gunshot injury linking two homicides to the same assailant

This case report describes an unusual pattern of gunshot firing that proved useful in convicting one assailant of two murders. The assailant fired into the first victim, successively through the same entrance hole at contact range. This technique of firing twice through the same hole was also demonstrable on his second victim in the bare skull of the decomposed body. This unusual pattern noted in two homicides found two weeks apart, in concert with other circumstantial evidence, led to the successful conviction of the man for both murders.     

Unusual motor ability in gunshot injury of the heart caused by a shotgun

In a case of shotgun-injury of the heart with complete rupture of both ventricles and lesion of the aorta the victim was able to move a few metres in approximately six seconds. Despite other opinions ability to move or act can be maintained in cases of severest injuries of the heart caused by missiles with high energy.     

Preliminary evaluation of the persistence of organic gunshot residue

The organic components of gunshot residue (OGSR, also called firearms discharge residue (FDR) or cartridge discharge residue (CDR)) have been studied and discussed in the literature. These residues, consisting of particulates such as burned and unburned powder as well as molecular compounds, are rarely used in casework except for purposes such as shooting reconstructions. Molecular compounds that survive the firing event or that are created as a result of the firing event could, with focused research and development, open a new avenue for forensic gunshot residue analysis. In this study, the persistence of organic gunshot residue was evaluated using diphenylamine (DPA) as a target analyte and ion mobility spectrometry (IMS) as the detection system. Samples were collected from hands using a solvent swabbing technique and the swab was analyzed using direct thermal desorption for sample introduction into the IMS. OGSR was found to persist for at least 4h. Although DPA is a widely used industrial compound, analysis of numerous blank and background samples (n～100) did not show any significant response for DPA using this detector. Variations were noted among individuals and as such, the data set does not support estimation of a half-life as has been done for traditional primer residues. No secondary transfers were observed, suggesting the possibility of skin adhesion via interactions between the lipophilic organic compounds and skin lipids. IMS proved valuable as a means of generating patterns for forensic pattern matching and shows promise as a screening tool applied to firearms discharge.     

Survey of gunshot residue analysis in forensic science laboratories

The purpose of this survey was to determine the methods of analysis being used on gunshot residue (GSR) samples in forensic science laboratories across the United States. In addition, the two general techniques of GSR analysis are compared and contrasted. Problems encountered by analysts using scanning electron microscopy/energy-dispersive X-ray analysis (SEM/EDX) are discussed.     

Analysis of gunshot residue test results in 112 suicides

The results of gunshot residue (GSR) tests in 112 suicide cases investigated by the U.S. Army Criminal Investigation Command over a ten-year period are described. Only suicide cases in which there was certainty that the victim fired a weapon were examined in an effort to reduce ambiguous results. Previous case work research by Rudzitis indicated that positive GSR test results were encountered in suicides 62% of the time using various combinations of neutron activation analysis (NAA) and atomic absorption spectrophotometry (AAS). Threshold values of 0.2-micrograms antimony and 0.3-micrograms barium (0.2-micrograms antimony and 0.5-micrograms barium after 1985) used by the U.S. Army Criminal Investigation Laboratory resulted in positive GSR results in suicide cases 38% of the time. The effects of time, location of body, handling of the body, weapon type, caliber, and condition of the hands on GSR results are examined. Case studies involving suicides by unit armorers are discussed.     

Formation of epidermal damage at entry by gunshot with a contact weapon

Examination of contact bullet wounds shows the patterned inprint of the muzzle on the skin ("stanzmark") and further ragged structures around the periphery to be the remainders of the abraded epithelium. Usually these are turned outwards and from arch-shaped intraepithelial recesses, which contain residual amounts of propellant. The damage and soiling around the point of entry are the result of two factors in combination: the combustion gases and the gases escaping between the skin surface and the front of the barrel. This leads to different amounts of skin abrasion dependent on the amount and pressure of the gases. In this way, the frequently seen difference in size and shape of the stanzmark and the muzzle front can be explained.     

头发对射击残留物附着的影响

利用射击残留物的存在和分布形态判断枪口与射入口的距离是现场分析的关键之一。然而我们在工作中发现,在对头部射击的案件中,弹孔周围的头发有可能对射击残留物起到屏蔽作用,尤其在贴近距离[1](2cm~5cm左右)射击的时候,绝大部分射击残留物会附着在头发而不是头皮上,本文将以实验和真实案例为基础详细说明近距离射击时头发对射击残留物附着的影响。     

A simple histochemical technique for the identification of gunshot residue

Alizarin red S (ARS) is a commonly used organic dye useful in the histologic identification of calcium deposits. ARS also forms colored reaction products with other metal ions, including barium and lead, which are present in primer residue. In histochemical studies, ARS is shown to identify primer residues from several manufacturers as well as primer residue deposited in tissue, either experimentally or in close-range gunshot wounds. This can be easily accomplished with routine histologic techniques. ARS does not stain gunpowder residue, tattoo pigment, melanin, graphite, india ink, or anthracotic pigment.     

Rapid search and quantitative analysis of gunshot residue particles in the SEM

Automated scanning electron microscopy coupled with image analysis and X-ray micro analysis was used to characterize a variety of gunshot residue (GSR) samples. More than 500 rounds of commercially available ammunition and six different types of hand gulls were used in the study of 17 GSR and 19 reference specimens. The individual particle X-ray composition was determined for 12 different elements. Elemental composition of GSR particles was highly variable but consistent with compounds mixed into or associated with a barium oxide matrix. When present in a specimen, GSR could be adequately characterized with automated procedures in less than an hour by restricting analyses to features larger than 2 microm. In "clean" samples, a higher resolution particle search was required to avoid reporting false negatives. Careful control of the back scattered electron signal strength threshold, by reference to a standard, was needed to ensure both time-efficient and accurate analyses. Samples collected from non-shooting subjects. active in a physical environment which contained firearms discharge residue were seen to be easily contaminated by sub-micron GSR particles.     

A method for the quantitative determination of nitrites in gunshot residue cases

This paper describes a method for the quantitative determination of nitrites present in gunshot residues, using an ultraviolet-visible spectrophotometer routinely employed in colorimetric procedures. The method involves the quantitative formation of a chromophoric complex between the nitrites present in the extracted gunshot residue and the analytical reagents. The procedure has been found to be sensitive enough to detect sub-microgram quantities of nitrites in gunshot residues, and has been successfully employed in the determination of muzzle-to-target distances, a question asked often in forensic science cases.     

Firing distance estimation through the analysis of the gunshot residue deposit pattern around the bullet entrance hole by inductively coupled plasma-mass spectrometry: an experimental study

The use of inductively coupled plasma-mass spectrometry (ICP-MS) in the study of gunshot residues (GSR) is relatively recent, and only a few studies have been published on the subject. In the present paper, this instrumental technique has been used to study the deposit pattern of the GSR around the bullet entrance hole, through the analysis of antimony (Sb), barium (Ba), and lead (Pb). The data obtained were used to establish a mathematical model for estimating the firing distance. Test shots using a 6.35-mm pistol were made against a target of cotton tissue, and the amounts of Sb, Ba, and Pb deposited in quadrangular pieces of the target, cut from 4 radial positions, were determined by ICP-MS. In these experimental conditions, it was possible to estimate the firing distance on the interval [20-80] cm. The best linear correlation between ln m and d, where m is the mass of Sb, Ba, or Pb in the samples, expressed in mug/g of target tissue, and d the firing distance, was obtained at radial distances between 3.5 cm and 4.5 cm from the entrance hole. The best regression curve which adjusted to the data was a linear multiple regression between the firing distance and the logarithm of the mass of each element: d = a + b(1)X(1) + b(2)X(2) + b(3)X(3), where X(1) = ln m (Sb), X(2) = ln m(Ba) and X(3) = ln m (Pb). The accuracy of firing distance estimation using only 1 or 2 elements was not significantly different from the one obtained with the 3 elements.     

Identification of serial homicide victims in the "Green River Murder" investigation

The Green River Murder Investigation in King County, Washington, is currently the longest and most active serial murder investigation in U.S. history. To date, little information has been reported on methods used in identification of serial murder victims. In this paper, various methods used in victim identification are reviewed and difficulties encountered during the course of the investigation are described. The experience of the authors is presented in order to acquaint other agencies with problems of victim identification associated with these serial murder victims and to provide key methods that may be useful in other such investigations.     

Development of a quantitative LC-MS/MS method for the analysis of common propellant powder stabilizers in gunshot residue

In traditional scanning electron microscopy/energy dispersive X-ray analysis of gunshot residue (GSR), one has to cope more and more frequently with limitations of this technique due to the use of lead-free ammunition or ammunition lacking heavy metals. New methods for the analysis of the organic components of common propellant powder stabilizers were developed based on liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). A multiple reactions monitoring scanning method was created for the screening of akardite II, ethylcentralite, diphenylamine, methylcentralite, N-nitrosodiphenylamine, 2-nitrodiphenylamine, and 4-nitrodiphenylamine, present in standards mixtures. Five out of seven of these target compounds can be selectively identified and distinguished from the two others with a high accuracy. Samples from the hands of a shooter were collected by swabbing and underwent solid phase extraction prior to analysis. Detection limits ranging from 5 to 115 mug injected were achieved. Results from several firing trials show that the LC-MS/MS method is suitable for the detection of stabilizers in samples collected following the firing of 9 mm Para ammunitions.     

Homicide-suicide by a single gunshot to the head

Apart from typical suicides, there are sometimes unusual deaths from gunshots to the head. The presented case is a double death from the autopsy material of the Institute of Legal Medicine in Berlin. The report deals with a murder-suicide of a man, who killed himself and his 2-year-old daughter by a single gunshot. After having administered a tranquilizer to the child, he held her head to his own and fired a contact shot to his right temple so that the bullet passed through both heads.     

The "skin-skull-brain model": a new instrument for the study of gunshot effects

In order to create and study wound morphology, a "skin-skull-brain model" had to be designed which would make the laboratory reproduction of a real ballistic injury possible.To simulate the human skin, an artificial skin (a silicon cap) is used. This silicon scalp contains synthetic fibers (artificial leather) to simulate the collagen and fat of the scalp. The artificial skull is a layered polyurethane sphere (19 cm o.d.; and 5, 6, or 7 mm thick) constructed in a specially designed form with a Tabula externa, Tabula interna, and a porous Diploe sandwiched in between. The periostium of the artificial skull is made of latex. This elastic latex layer prevents the bone fragments from scattering after the model has been struck by gunfire. The brain itself is simulated with ordnance gelatin, 10% at 4 degrees C, a material well known in wound ballistics. Gunshots were fired at a distance of 10 m from the model.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 injuries.Using the "skin-skull-brain model" has 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 inflicted traumas.     

Spousal homicide and the subsequent staging of a sexual homicide at a distant location

The case of a 63-year-old man who killed his 52-year-old wife and then staged a sexual homicide at a distant location is reported. A review of all evidence, a forensic psychological interview, and psychological testing indicated that the murder was the result of a narcissistic rage reaction during which the subject beat his wife to death with a paint can, a clothing iron, and a rock. He then drove her body to a field 87.3 miles away, and positioned it in a manner that exposed her breasts and her underwear. He turned himself into the police two days later. There is no controlled empirical research on staging, although this single case supports the criminal investigative theory that staging exists, and is done to deliberately mislead homicide investigations (Douglas et al., 1992).     

Confusing injury findings in a suicidal gunshot fired to the chest from a carbine with a sawed-off barrel

The stellate bullet entrance wound is one of the facultative features of a contact shot. For the formation of a star-shaped wound two factors are of special importance: first, an extensive bony support underlying the skin in the entrance region, and second, a strong propellant charge of the cartridge fired. Contact shots to the precordial region usually do not cause stellate entrance wounds, even if high-powered rifle ammunition is used. In the reported case, an injury pattern was observed that was not in line with normal findings and seemed confusing at first. Following a suicidal gunshot to the chest from a sawed-off carbine 98a (cal. 8 x 57 Js), a 4.5 cm wide, gaping bullet entrance wound with radiating tears was found. Instead of the usual pocket, the anterior thoracic wall showed a fist-sized area of destruction with extensive undermining of the subcutis. Not far from the entrance hole, a rib fragment had become displaced retrogradely thus perforating the skin from the inside out. The unusual pattern of findings could be explained by the fact that the barrel had been sawed off: as a result of this manipulation, a considerable part of the propellant charge had been converted outside the barrel, i.e. in the initial section of the bullet path.     

Atypical injury pattern of a pedestrian run over by an unimog in the epigastric region

Strongly intoxicated, a 37-year-old man fell in front of the right back wheel of an emergency vehicle (MB Unimog) and was run over according to eye witnesses. He died in hospital shortly afterwards. The autopsy revealed that he bled to death from a traumatic liver rupture (bursting of the right hepatic lobe and severing of a piece of tissue measuring 17 x 8 x 4 cm). There were no injuries classicaly seen in victims run over by a car. The atypical injury findings in this case are due to the special features of the accident vehicle: The Unimog (an all-wheel vehicle with a fixed rear axle and flat coils) struck the right side of the body lying on the street with its rear wheel and was then lifted over the body by its fixed axle without touching the left side.     

The future of homicide offenders. Results from a homicide project in Copenhagen

As a part of a Copenhagen homicide project, 52 released homicide offenders were followed during a mean period of 9 years. Pessimistic expectations were confirmed as post-release rates of criminality, psychiatric admission, and suicide were all very high. By logistic regression analyses, young age by release, and long stay in prison were found to increase the risk of further criminality, and previous psychiatric admission was found predictive of future admission. The problems in using logistic regression analysis on variables--all of whom may be viewed as "parallel" indicators of a common tendency to adverse behaviors--are discussed. In conclusion, the results have been used for a tentative division of homicide according to the offender-victim relationship into intra-family homicide and extra-family homicide. In intra-family homicide the most important dimension seems to be the psychic state of the offender, in extra-family homicide more impact should be attributed to the social dimension.