A study of dispersion of gunshot residue from a frequently used Serbian ammunition cal. 7.65 mm to support selected aspects of casework in North Macedonia.

The subject of this research was the inorganic gunshot residue component collected from shooting patterns obtained on woven cotton cloth using a Pietro Beretta model 70 pistol, cal. 7.65 mm and Serbian ammunition for the following muzzle-to-target distances: 25, 50, 75, 100 and 125 cm. For each distance, three rounds of shooting were performed. Particles were lifted within a 10 cm radius of the projectile entrance and automatically analyzed using a scanning electron microscope coupled with an energy dispersion X-ray spectrometry. The obtained data on the populations of particles were analyzed taking into account their numbers, chemical classes and sizes. The results showed an apparent maximum incidence within all particles containing barium at about 50 cm distance. Also, lead particles revealed a distinct behaviour, being dominant at a 25 cm distance, falling below the other chemical classes, and finally becoming dominant again at 125 cm. The analysis of the frequency of occurrence of particles sorted according to their sizes confirmed that the small particle population is the largest, and their distribution in function of the equivalent circle diameter is exponential-like. The obtained results provided knowledge on the distribution of particles in the vicinity of the tested firearm and ammunition cal. 7.65 mm which generally corroborates with similarly studied GSR distributions obtained for the use of pistols cal. 9 mm. This information, together with the examinations of gunshot damages and other types of residues such as soot or unburned propellant grains may support qualitative inferences on shooting distance estimation, especially in cases, when the firearm and cartridges are not available to perform test shooting. In such cases even roughly estimated shooting distance can be helpful, e.g. for confirming or excluding the possibility of self-inflicted injuries or suicide and infer on the mutual position of the shooting stage actors. An example of casework that illustrates intermediate shooting distance estimation is presented.

Effects of the interaction of gunshot residue plume and cotton fabrics-an empirical study towards extensive assessment of close-range shooting distance.

Shooting distance assessment is a substantial problem in forensic investigation of suicides and homicides committed by means of a firearm. There are cases when the gun or ammunition used in a crime or both are not available for forensic testing and so reference shooting patterns cannot be obtained for shooting distance assessment with chemographic methods. In such cases, the shooting distance evaluation has to rely solely on the evidence of gunshot wounds in human tissues and clothing. To facilitate a robust assessment of the shooting distance in such circumstances, the effects of contact and close-range shooting using a 9 mm Luger pistol and traditional types of ammunition on different popular types of cotton textiles were examined. This study is focused not only on the distribution of gunshot residue but also on changes undergoing within the textiles. Both chemical and morphological examinations of the deposited gunshot residue and characterisation of the changes in the fibres of the selected textiles were performed by means of optical microscopy, scanning electron microscopy and energy dispersive X-ray spectrometry as well as infrared spectrometry. It was established that not only the appearance of the shooting pattern but also the distribution of gunshot residue, being collected from the perimeter of 5 cm around the gunshot hole, depends on the properties of the textiles, i.e. their type, structure, density and thickness. In addition, it was found that on the surface of changed fibres, being collected from the edges of contact and near-contact shots, there were present numerous spherical inorganic residues of diameters usually much smaller than 1 micrometre.

Controversial Suicide Case Using a Submachine Gun with a Sound Suppressor-The Need of Team Work of Forensic Chemistry and Firearm Examiners.

Evidence materials in a presumed suicide case were studied by a firearm examiner and a forensic chemist. The victim's body with double gunshot wounding in his forehead, a machine gun in the sustained fire mode with a silencer, and four cartridge cases were found. Examinations of the evidence, the case file studies, and experiments dedicated to the case were carried out. Relationships between the placement of cartridge cases and the gun were established using a fast camera. The distributions of gunshot residues on the evidence materials and within the comparative gunshot patterns were studied by means of optical and electron microscopy, X-ray microanalysis, and infrared spectroscopy. The shooting distance was assessed to be 30 cm or more, whereas the greatest distance that could have been achieved by the victim himself was about 11-13 cm. The obtained results supported the version of homicide rather than suicide.

Trends in analysis of gunshot residue for forensic purposes.

Detection and identification of organic and inorganic components of gunshot residue are well established within forensic chemistry because of highly characteristic and uncommon features of the products of ammunition discharge at the time and place of a shooting incident in comparison to other materials present in daily life of people. Both types of residue play an important role in establishing various circumstances of a shooting crime, though the most vital one concerns the possibility of relating a suspect with the activity of shooting. In this aspect, solid, inorganic particles, nowadays called characteristic, have been utilized. Their specific features result from the primer mixture composition, including compounds of heavy metals, lead, antimony, and barium, and from the extraordinarily dynamic conditions of their formation, taking place at the moment of the primer detonation. Scanning electron microscopy and X-ray microanalysis techniques proved to be necessary and sufficient to reveal the content and the spherical morphology of the particles for this purpose. Recently, the recommendation that the potential for lead exposure be minimized was followed in the production of ammunition cal. 9 mm Luger, 0.40 S&W, 0.380 Auto, and 0.38 Special. These modern types of ammunition expel less characteristic particles, the identification of which can be a challenge for the examiners. At least two solutions to strengthen the residue identity are taken into account: additional insights into the internal structure of inorganic particles, e.g., by means of electron backscattered diffraction and focused ion beam, as well as complementary examinations of organic residues with sensitive mass spectrometric techniques.

A study of gunshot residue distribution for close-range shots with a silenced gun using optical and scanning electron microscopy, X-ray microanalysis and infrared spectroscopy.

Detailed physical and chemical analysis of gunshot residue deposited in the nearest vicinity of a submachine gun alone and with a sound suppressor was performed. The studies were inspired by recent shooting cases with the use of a firearm with a silencer and the need to estimate the shooting distance to human body naked and covered with clothing. A series of experiments were performed in the shooting range using a machine pistol and the appropriate ammunition cal. 7.65mm Browning. Targets were placed in the range of 0-30cm from the gun and covered either with white cotton fabric or a porcine skin that mocked people's clothing and the naked skin. Both the organic and inorganic residue were examined by means of optical microscopy, infrared spectrometry as well as scanning electron microscopy and energy dispersive X-ray spectrometry. The influence of factors, such as sound suppressor, shooting distance and the substrate type on the mechanism of particles spread and their availability for research was established and discussed.

Chemical and physical characterisation of welding fume particles for distinguishing from gunshot residue.

Spherical particles produced by firearms loaded with a traditional ammunition reveal characteristic elemental contents and so their identification may provide a significant evidence in criminal investigations. With the advent of modern technologies in manufacturing ammunition, which replace toxic compounds of lead, antimony and barium in the primer mixture by elements and compounds such as powdered aluminium, titanium, amorphous boron or calcium silicide, differentiation between gunshot residue and morphologically similar particles originating from other anthropogenic or natural sources becomes more difficult. This work provides a chemical and morphological characterisation of welding fume particles originating from both the core and the covering of electrodes used in popular manners of welding steel and aluminium alloy constructions. With the use of scanning electron microscopy and energy dispersive X-ray spectrometry it has been established that single spherules containing aluminium, titanium or a set of such elements as aluminium, silicon, potassium and calcium may occur in result of welding processes, however, they are accompanied by great numbers of iron and iron oxide spherules. Thus, with this analytical method a population of welding particles can be distinguished from a population of gunshot residue originating from a modern type of ammunition, but a special care has to be taken when assessing the evidential value of single or few spherules consisting from light elements being detected in result of the search for gunshot residue for forensic purposes.

Scanning electron microscopy and X-ray microanalysis for chemical and morphological characterisation of the inorganic component of gunshot residue: selected problems.

Chosen aspects of examinations of inorganic gunshot particles by means of scanning electron microscopy and energy dispersive X-ray spectrometry technique are presented. The research methodology of particles was worked out, which included a precise and repeatable procedure of the automatic detection and identification of particles as well as the representation of the obtained analytical data in the form of the frequencies of occurrence of particles of certain chemical or morphological class within the whole population of particles revealed in a specimen. On this basis, there were established relationships between the chemical and morphological properties of populations of particles and factors, such as the type of ammunition, the distance from the gun muzzle to the target, the type of a substrate the particles sediment on, and the time between shooting and collecting the specimens. Each of these aspects of examinations of particles revealed a great potential of being utilised in casework, while establishing various circumstances of shooting incidents leads to the reconstruction of the course of the studied incident.

Interactions of chromium ions with starch granules in an aqueous environment.

In this study, interactions of dichromate ions with potato starch granules in highly acidic aqueous solutions and at different temperatures were investigated. It was found that the process underwent a reduction of Cr(2)O(7)(2-) to Cr(3+) accompanied by the formation of intermediate Cr(5+) ions detected by electron paramagnetic resonance (EPR) spectroscopy. The reactions took place after the attachment of dichromate anions to the granules and resulted in a lowering of the Cr(2)O(7)(2-) initial content in the solution. The newly formed Cr(3+) ions were both accumulated by the granules or remained in the solution. It was observed for the first time that the quantity of such ions taken by the granules from the solution was noticeably higher than that delivered by trivalent chromium salt solution. It was revealed by scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDX) that the chromium ions were not only adsorbed on the granule surface but also introduced into the granule interior and evenly distributed there. An activation energy of the reduction reaction equal to 65 kJ·mol(-1) and the optimal parameters of the process were established. The proposed mechanism could be useful for the bioremediation of industrial effluents polluted by hexavalent chromium compounds.

On the prevalence of gunshot residue in selected populations - an empirical study performed with SEM-EDX analysis.

The study was designed to obtain a comprehensive view on the prevalence of gunshot residue and the factors influencing their dispersion. 273 specimens collected from people of various professions, representing both users and non-users of firearms, as well as from the interior of a forensic laboratory were examined for the presence of gunshot residue. In specimens taken from hands of 100 people declaring no contact with firearms only one spherical particle containing lead, antimony and barium was found. Numbers of particles found in specimens collected from hands of 50 shooters varied from zero to numbers greater than 100 and were strongly correlated with the time interval between last shooting and collecting specimens. Within the first 4h after shooting particles are being lost from the shooter's hands, and so transferred from shooters to their environment. Thus, the relatives of five hunters were examined during both the close and open hunting seasons to trace the potential secondary transfer in practice. Using the criterion of low risk of contamination with gunshot residue, i.e. 5h after last handling a gun, only few specimens were encountered among these collected from hands of firearm users that contained characteristic particles and these occurred in small numbers. Frequent shooters, e.g. shooting instructors or firearm examiners, formed a class for themselves of high risk of contamination with gunshot residue. As a result of continuous monitoring of the laboratory (55 specimens examined so far), where the examinations of gunshot residue are being carried out, it has been proved that the laboratory is free from contamination and so confirmed the usefulness of protocols worked out. The obtained information provided empirical bases to the minimisation of the risk of contamination of the evidence as well as for the evaluation of the analytical findings in the expertise on gunshot incidents.

Chemical and morphological study of gunshot residue persisting on the shooter by means of scanning electron microscopy and energy dispersive X-ray spectrometry.

Persistence of gunshot residue (GSR) simultaneously collected from hands, face and hair, and clothing of the shooting person was examined. Samples were collected from five shooters in nine time intervals after a single shoot with a Luger 9 mm pistol, in the range of 0-4 h and examined with scanning electron microscopy and energy dispersive X-ray spectrometry. Numbers of particles, frequencies of occurrence of certain compositions of particles, and their sizes in function of the time intervals were inspected. The greatest numbers of particles were observed in samples collected from hands right after shooting, but they decrease quickly with time. In samples collected from the face smaller initial numbers of particles were found, but they lasted at a similar level longer. The estimated half-life times of particles were less than 1 h for samples taken from the hands, over 1 h for clothing and about 2-3 h for the face. In samples collected at longer intervals after shooting, there were particles present of small sizes and irregular shapes. The results demonstrate that including evidence collected from the suspect's face and hair may increase the probability of detection of GSR in cases when the suspect has not been apprehended immediately after the investigated incident.

Variation of the chemical contents and morphology of gunshot residue in the surroundings of the shooting pistol as a potential contribution to a shooting incidence reconstruction.

A study of the chemical contents and sizes of gunshot residue originating from 9×18mm PM ammunition, depositing in the vicinity of the shooting person was performed by means of scanning electron microscopy and energy dispersive X-ray spectrometry. Samples of the residue were collected from targets placed at various distances in the range 0-100cm as well as from hands and clothing of the shooting person. Targets were covered by fragments of white cotton fabric or black bovine leather. In the case of cotton targets microtraces were collected from circles of 5 and 10cm in radius. Results of the examinations in the form of numbers of particles, proportions of their chemical classes and dimensions revealed a dependence on the distance from the gun muzzle, both in the direction of shooting and in the opposite one, i.e., on the shooting person. The parameters describing gunshot residue differed also depending on the kind of the target substrate. The kind of obtained information gives rise to understanding the general rules of the dispersion of gunshot residue in the surroundings of the shooting gun. Thus, it may be utilised in the reconstruction of shooting incidences, especially in establishing the mutual positions of the shooter and other participants of the incident.

[Forensic examinations of clothing and other materials found in the coffin by the body of general Wladyslaw Sikorski]. / Kryminalistyczne badania odziezy i pozostalych materialów ujawnionych przy zwlokach w trumnie generata Wladyslawa Sikorskiego.

The report presents the results of identification of garments and other textile products, as well as various materials, e.g. fragments of metals, wood slivers and chemical substances found in the coffin by the body of General Wladyslaw Sikorski. The articles of clothing revealed no damages that could have resulted from a thermal factor, such as fire, high temperature or explosion. Mechanical damages of fabric and knitted fabric resulted from annealing processes and biodegradation of the products. Metallic particles present near the body were fragments of the solder sealing the cover with the coffin. A wood sliver revealed in the left orbital cavity and some of the slivers found on the surface of the shirt originated from Douglas-fir, and other splinters most probably from cypress and elm tree. The presence of struvite, the product of binding of phosphates, ammonia and water resulting from decay of biological materials in the presence of magnesium compounds, was established on the surface of the shirt and the handkerchief.

[Analysis of biological material originating from the body of general Wladyslaw Sikorski for inorganic poisons and diatoms presence]. / Badania materialu biologicznego pochodzacego ze zwlok generala Wladyslawa Sikorskiego na obecnosc trucizn nieorganicznych i okrzemek.

Results of the analysis of biological materials originating from the body of general Sikorski are presented in the paper. Samples of the liver, kidney, intestine and lung were analysed for metals and As content, and samples of the lung, liver, kidney, stomach, intestine and bone marrow--for diatoms presence. The analysis for metals and As was performed by atomic absorption spectrometry (AAS) and inductively coupled plasma optical emission spectrometry (ICP-OES). Before the analysis, the samples were wet digested by the classic and microwave assisted method. The analysis did not result in detecting the presence of As, Co, Ni, and Tl in any of the studied materials, while Hg was not revealed in the liver, intestines and lung and Pb in the intestines and lung. The content of Ba, Cd, Cr, Cu, Fe, Mn, Sr and Zn in all the studied materials, Hg in the kidney, and Pb in the liver and kidney did not indicate poisoning by the above-mentioned metals or arsenic. No diatoms were found in the studied materials.

A fatal shot with a signal flare--a crime reconstruction.

A reconstruction of an incident of a fatal wounding of a football fan with a parachute flare was performed. Physical and chemical examinations of the victim's trousers and parts of a flare removed from the wound in his leg were performed by means of an optical microscope and a scanning electron microscope coupled with an energy dispersive X-ray spectrometer. Signs of burning were seen on the front upper part of the trousers, including a 35-40 mm circular hole with melted and charred edges. Postblast residue present on the surface of the trousers contained strontium, magnesium, potassium, and chlorine. Also the case files--the medical reports and the witnesses' testimonies--were thoroughly studied. It has been found that the evidence collected in the case supported the version of the victim being shot by another person from a distance.

Distribution and properties of gunshot residue originating from a Luger 9 mm ammunition in the vicinity of the shooting gun.

Examinations of various features of gunshot residue (GSR) collected from targets in a function of the shooting distance as well as from hands and the forearm, front and back parts of the upper clothing of the shooting person were performed with SEM-EDX. GSR samples were obtained using Walther P-99 pistol and Luger 9 mm ammunition of Polish production. The experiments were designed in such a manner that the substrates for collecting GSR reminded the ones usually obtained for examinations within criminal cases. Results of the performed examinations in the form of parameters describing GSR particles: the number of GSR, proportions of their chemical classes as well as their sizes revealed a dependence on the shooting distance both, in the direction of shooting and backwards, i.e. on the shooting person. The analysis of the distribution of particles in the vicinity of the shooting gun may be utilised in description of the general rules of the dispersion of GSR as well as in the reconstruction of a real shooting case.

Grouping of ammunition types by means of frequencies of occurrence of GSR.

An attempt was made to build a classification scheme for gunshot residues (GSR) samples originating from four types of ammunition, collected from shooters' hands immediately after shooting. The secured material was examined with the use of SEM-EDX method in the automatic manner. The obtained results were expressed as frequencies of occurrence of particles assigned to various chemical classes. In order to establish the most discriminative of these features the Mann-Whitney test was performed. Cluster analysis was performed for grouping the analysed samples according to their origin, i.e. the type of ammunition. It has been found that samples of GSR originating from Browning 7.65 mm and Luger 9 mm ammunition can be fairly easy differentiated from the remaining samples, whereas samples of GSR originating from of Makarov 9 mm and these of Tokarev 7.62 mm could not be differentiated using frequencies of occurrence of particles in the selected chemical classes.