Machine washing or brushing of clothing and its influence on shooting distance estimation.

Experiments were conducted to assess the effect of machine washing or brushing of clothing items on Gunshot Residue (GSR) patterns (gunpowder residues, lead, and copper, deposits) around bullet entrance holes. Results show that those treatments decrease considerably the amount and density of GSR. However, for close shooting distances not all of the GSR deposits are removed. Remaining patterns may be visualized by specific color reactions and used for shooting distance estimation.     

Gunshot residue testing in suicides: Part II: Analysis by inductive coupled plasma-atomic emission spectrometry

Several different methods can be employed to test for gunshot residue (GSR) on a decedent's hands, including scanning electron microscopy with energy dispersive x-ray (SEM/EDX) and inductive coupled plasma-atomic emission spectrometry (ICP-AES). In part I of this 2-part series, GSR results performed by SEM/EDX in undisputed cases of suicidal handgun wounds were studied. In part II, the same population was studied, deceased persons with undisputed suicidal handgun wounds, but GSR testing was performed using ICP-AES. A total of 102 cases were studied and analyzed for caliber of weapon, proximity of wound, and the results of the GSR testing. This study found that 50% of cases where the deceased was known to have fired a handgun immediately prior to death had positive GSR results by ICP/AES, which did not differ from the results of GSR testing by SEM/EDX. Since only 50% of cases where the person is known to have fired a weapon were positive for GSR by either method, this test should not be relied upon to determine whether someone has discharged a firearm and is not useful as a determining factor of whether or not a wound is self-inflicted or non-self-inflicted. While a positive GSR result may be of use, a negative result is not helpful in the medical examiner setting as a negative result indicates that either a person fired a weapon prior to death or a person did not fire a weapon prior to death.     

Distribution of GSR particles in the surroundings of shooting pistol

Several series of experiments were performed to study the distribution of GSR particles in seven directions in the surroundings of shooting firearm (pistol CZ 85 caliber 9 mm Luger). External and internal conditions and two different primer types were used for the shooting experiments. The results showed that maximum number of GSR particles could be found in the right front quadrant at a distance of 2–4 m with respect to the shooting firearm position and shooting direction. GSR particles were even found in distance 10 m from shooting firearm. A significant influence of climatic conditions on GSR distribution was confirmed.     

Interpretation of unusual wounds caused by firearms.

The interpretation of the range of fire of gunshot wounds requires coordination of information and observations from the autopsy surgeon, scene investigator, and laboratory analyst. Opinions based on incomplete information often lead to misinterpretation of the wound. The effects of interposed targets such as clothing, windows, and body parts are discussed. Case examples are given for interposed targets that cause confusing patterns and even lead to misidentification of the points of entrance and exit of the projectile in the body. The splitting of tissue in areas of bony prominence can be mistaken for evidence of discharge of a firearm at close range.     

Gunshot residues on dry bone after decomposition-a pilot study

Abstract: Very little literature exists concerning radiochemical and microscopic analyses of gunshot wounds in decomposed material, and even less concerning skeletonized samples; the most advanced technologies may provide useful indications for the diagnosis of suspect lesions, especially if gunshot wounds are no longer recognizable. However, we know very little of the survival of gunshot residues (GSR) in skeletonized samples. This study examined nine gunshot wounds produced on pig heads which then underwent skeletonization for 4 years, and four gunshot entries on human heads from judicial cases which were then macerated to the bone in water; the samples underwent scanning electron microscopy coupled with energy dispersive X‐ray (SEM‐EDX) analysis. Positive results for GSR were observed only in four of the nine animal samples and in all four human samples. Among the human samples, two lesions showed Pb and Sb, one lesion only Pb, and one Pb, Sb, and Ba. This pilot study showed the survival of GSR in skeletal material and therefore the crucial importance of SEM‐EDX analyses on skeletonized material. Further studies are needed in order to ascertain the role of environmental modifications of GSR.     

Automatic rifle injuries: suicide by eight bullets. Report of an unusual case and a literature review

A 25-year-old man committed suicide by shooting himself with eight bullets fired from a military rifle set on automatic. This rifle has two firing modes: an automatic mode and a self-loading, single-shot mode. Using this case as an example, some important aspects of firearm injuries are discussed with special emphasis on those points that are relevant to automatic military rifles and most applicable to forensic pathology practice. Some of the pathologic features of firearm wounds are reviewed and the role of the pathologist is discussed. Lastly, the most important points that help the pathologist to determine the type or nature of a firearm death--that is, whether it is an accident, homicide, or a suicide--are discussed. Classically, the number of the firearm wounds is used to differentiate suicide from homicide. As in the case reported here, however, when an automatic rifle or a military rifle set on automatic is used, the number of wounds is not a reliable indicator of the type of death.     

New observations on cutaneous firearm wounds

The authors describe the aspect of the dermal surface in firearm wounds. In entrance wounds, the abraded area is rather evident, with loss of the papillary pattern and lacerations of the basement membrane. Exit wounds appear as irregularly lacerated interruptions, with protruding collagen fibers; the surrounding dermis has nearly undamaged papillae. Also described, still on the dermal surface, are the flame effect and the powder tattooing. Evident lesions of the basement membrane, produced by the grains of powder, can be observed. Particles [gunshot residues (GSR)] are often recognizable lying on the dermal surface or entrapped among the collagen fibers of the superficial dermis.     

Fate and Behavior of Gunshot Residue—A Review

A review of the literature concerning the fate and behavior of gunshot residue (GSR) is presented. A number of concomitant parameters including firearm and ammunition type, plume and GSR material characteristics, travel distances, chemical composition and GSR morphology are critically discussed in relation to their effects on the distribution and deposition, transfer and persistence processes of GSR. The underlying mechanisms associated with such processes are also considered. Knowledge of these processes on GSR materials could provide valuable information concerning scene preservation and subsequent forensic sampling. The number of GSR particles deposited can vary significantly with each firearm discharge, highlighting the potential to produce distinctive data in each individual case. With the continual development and compositional changes of new ammunition types, further evaluation of the effect these processes may have on GSR evidence and their possible influence on the interpretation of the analytical results should be given due consideration.     

Comparison of GSR Composition Occurring at Different Locations Around the Firing Position

Abstract: Variations in gunshot residue (GSR) compositions are used in the reconstruction of shooting incidents. In this study, GSR samples taken from seven different locations around and in the firearm were collected and analyzed using scanning electron microscopy/energy dispersive X‐ray analysis. Four different types of ammunition were applied. Very low correlations were found when different ammunition were used. This clearly shows that it is possible to differentiate between ammunition types. When the same ammunition was used, high correlations were found between samples taken from external positions (such as hands of shooter, bullet‐entrance holes) but poor correlation was found between internal samples (such as firearm barrel, cartridge case) and external samples. A high degree of association was found between samples that simulated victim and shooter. These findings clearly demonstrate that GSR comparison studies are meaningful but care needs to be taken when choosing suitable exhibits. External samples (such as hands of shooter, bullet‐entrance holes) are more suitable candidates than internal samples (barrel of the firearm, cartridge case).     

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.     

Improved method for shooting distance estimation. Part 1. Bullet holes in clothing items

An improved method for firing distance estimation on clothing is described. The novel part of the method includes transfer of total nitrite (nitrite ions and smokeless powder residues) from the target to an adhesive lifter. After the transfer, lead and copper deposits around the bullet entrance hole are visualized by rhodizonate and rubeanic acid, respectively. The Modified Greiss Test is carried out after alkaline hydrolysis of the smokeless powder residues on the adhesive lifter.     

Gunshot residue testing in suicides: Part I: Analysis by scanning electron microscopy with energy-dispersive X-ray

Several different methods can be employed to test for gunshot residue (GSR) on a deceased person's hands, including scanning electron microscopy with energy-dispersive x-ray spectroscopy (SEM-EDX) and inductively coupled plasma-atomic emission spectrometry (ICP-AES). Each of these techniques has been extensively studied, especially on living individuals. The current studies (Part I and Part II) were designed to compare the use and utility of the different GSR testing techniques in a medical examiner setting. In Part I, the hands of deceased persons who died from undisputed suicidal handgun wounds were tested for GSR by SEM-EDX over a 4-year period. A total of 116 cases were studied and analyzed for caliber of weapon, proximity of wound, and results of GSR testing, including spatial deposition upon the hands. It was found that in only 50% of cases with a known self-inflicted gunshot wound was SEM-EDX positive for at least 1 specific particle for GSR. In 18% of the cases there was a discernible pattern (spatial distribution) of the particles on the hand such that the manner in which the weapon was held could be determined. Since only 50% of cases where the person is known to have fired a weapon immediately prior to death were positive for GSR by SEM-EDX, this test should not be relied upon to determine whether a deceased individual has discharged a firearm. Furthermore, in only 18% of cases was a discernible pattern present indicating how the firearm was held. The low sensitivity, along with the low percentage of cases with a discernible pattern, limits the usefulness of GSR test results by SEM-EDX in differentiating self-inflicted from non-self-inflicted wounds.     

A preliminary investigation into the use of FTIR microscopy as a probe for the identification of bullet entrance holes and the distance of firing

FTIR spectroscopy has been found to be a valuable probe for the analysis of the distribution of organic components such as nitroglycerine in gunshot residues deposited on and around the bullet entrance hole of the clothing of the victim in short range firearm discharges. The method can be utilised for the detection and estimation of organic gunshot residues (OGSR) on the hands and clothing of the shooter. The method is specific and sensitive and is likely to be free from interference from, for example, environmental pollution. The method shows potential to be utilised as a suitable alternative to the widely used SEM-EDX analysis of the total contents of lead, barium and antimony present in the gunshot deposits around the bullet entrance hole. The method was tested in the laboratory and the results were validated by Gas Chromatography-Mass Spectrometry (GC-MS).     

根据创口射击残留物推断“5.4”式手枪射击距离的研究

目的利用环境控制扫描电镜/能谱仪（SEM/EDX）研究枪弹创射入口周围射击残留物与射击距离的关系,探讨其能否用于射击距离的判断。方法采用＂＂5.4＂＂式手枪分别在5、10、15、20、30、40、50、60、70、80、90、120cm处射击乳猪皮肤,利用SEM/EDX观察创口周围GSR的分布和成分,并建立回归方程。结果射击距离和GSR颗粒数量之间总体表现为直线关系,并建立了相应的回归方程。当射击距离为10~90cm时,用该方程推断射击距离效果较好。结论检测创口周围GSR可望用于判断“5.4”式手枪的射击距离。     

Implementation and Optimization of the Sodium‐Rhodizonate Method for Chemographic Shooting Distance Estimation

In shooting incident investigations where it is important to estimate the shooting distance, the sodium‐rhodizonate coloring method has been used for the visualization of GSR patterns extensively. This publication describes the optimization of this method by the use of a heated press for the transfer of GSR traces on garments, as well as variation of a number of other important process parameters. Our final aim for this project was to prepare a formal validation of the coloring method as prerequisite for its inclusion into the scope of ISO17025‐certified methods in the GSR Laboratory. A number of important factors and process parameters were identified, such as buffer composition and pH, type of textile used as a substrate and resolution of the documentation of the results. Results were tested using a synthetic proficiency test. Our optimized method has been found to be a very effective technique for visualization of macroscopic GSR traces.     

Vacuum collection of gunpowder residues from clothing worn by shooting suspects, and their analysis by GC/TEA, IMS, and GC/MS

Experiments were conducted to collect gunpowder (propellant) residues from shooters' clothing by vacuum and to analyze them by gas chromatography/thermal energy analyzer (GC/TEA), ion mobility spectrometry (IMS), and gas chromatography/mass spectrometry (GC/MS). The residues were collected on fiberglass and Teflon filters using the portable vacuum sampler, all supplied with the IMS instrument. Several solvents were examined for the extraction of the propellant components from the filters. The extracts were centrifuged and/or filtered, concentrated by evaporation, and analyzed without any additional clean-up procedure. Based on the results of the study, an operational method for analysis of gunpowder residues was introduced into casework without changing the present operational technique for gunshot (primer) residue (GSR) analysis on clothing implemented by the Israel Police. In the modified method, the clothing is first sampled by double-side adhesive-coated aluminum stubs (the tape-lift method) for GSR analysis (the existing method), followed by vacuum collection for propellant residue examination. The issue of interpretation of the analytical results is discussed.     

Discharge of a Pistol Out a Car Window with the Breech Within the Interior of the Car: Analysis of Gunshot Residue on a Car's Interior Surfaces

The defendant, the driver of the questioned car, allegedly extended his right arm over the passenger seat and fired a single shot from a 380 pistol out the passenger window with the pistol's breech within the car. A simulation of this shooting scenario using the same model car, but different year, was conducted to quantitate gunshot residue (GSR) contamination of interior surfaces within the car. The test car's dash and headliner/window frame above the pistol had the heaviest GSR contamination. The dash GSR from airborne deposition documents a firearm discharge within the vehicle. Transfer from GSR‐contaminated hands or clothing to the dash is unlikely. The heavy GSR contamination of the headliner/window frame above the pistol likely documents the window from which the pistol was fired, but additional experiments are needed to verify.     

Image analysis of gunshot residue on entry wounds: I – The technique and preliminary study

An automated image analysis (IA) technique has been developed to obtain a measure of the amount (i.e. number and area) of gunshot residue (GSR) particles within and around a gunshot wound. Sample preparation and IA procedures were standardised to improve the reproducibility of the IA measurements of GSR. Measurements of GSR from test firings into goat hide were enhanced by staining the barium and lead components present on the skin sections with Alizarin Red S. The amount of GSR detected on the stained skin sections was compared with backscatter electron micrographs of the same sections. The differences were deemed to be insignificant when the variability in the repeated test firings were taken into consideration. Preliminary results indicated that the decreasing relationship between firing range and the amount of GSR deposited was non-linear, and that for firing ranges of up to 20 cm the amount of GSR deposited from repeated shots fired from the same distance was highly variable.     

Image analysis of gunshot residue on entry wounds: II – A statistical estimation of firing range

A statistical investigation of the relationship between firing range and the amount and distribution of gunshot residue (GSR), used automated image analysis (IA) to quantify GSR deposit resulting from firings into pig skin, from distances ranging between contact and 45 cm. Overall, for a Ruger .22 semi-automatic rifle using CCI solid point, high velocity ammunition, the total area of GSR deposit on the skin sections decreased in a non-linear fashion with firing range. More specifically there were significant differences in the amount of GSR deposited from shots fired at contact compared with shots fired from distances between 2.5 and 45 cm; and between shots fired from a distance of 20 cm or less, with shots fired at a distance of 30 cm or more. In addition, GSR particles were heavily concentrated in the wound tract only for contact and close range shots at 2.5 cm, while the particle distribution was more uniform between the wound tract and the skin surfaces for shots fired from distances greater than 2.5 cm. Consequently, for future scientific investigations of gunshot fatalities, once standards have been established for the weapon and ammunition type in question, image analysis quantification of GSR deposited in and around the gunshot wound may be capable of providing a reliable, statistical basis for estimating firing range.