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.     

Homicide-suicide (dyadic death), homicide, and firearms use in England and Wales

Homicide-suicide forms a distinct form of homicide. An analysis of cases in the Yorkshire and Humberside region of England between 1991 and 2005 revealed 37 episodes with 42 victims. Previous studies have shown a high rate of use of firearms. Over the last 2 decades firearms legislation has become more restrictive. In this study all assailants were male, mean age 46.8 years. The commonest method of homicide was strangulation (36%) with 16% killed by firearms. This is a reduction compared with a previous study in the same region. All killers who shot their victims killed themselves with firearms. There were no multiple killings with firearms in this study and no stranger killings. Hanging was the commonest method of suicide. During the same period the use of firearms as a method of homicide increased in England and Wales with handguns, the most common weapon. Nationally, suicide after homicide has remained at a similar rate over the half century and is an uncommon phenomenon. Firearms use remains low in both homicide and homicide-suicide episodes in England, and further analysis is required to determine changes in patterns of killing.     

Swabbing firearms for handler's DNA

Obtaining quality DNA profiles from firearms can be instrumental in assisting criminal investigations. Typically, swabbings of firearms for handler's DNA are conducted on specific regions of the firearm prior to submission to the laboratory for analysis. This review examines and compares 32 cases whose gun swabbings were either analyzed individually according to the specific region which was swabbed, or analyzed collectively by combining the swabbings from all the individual areas. Those firearms whose swabs were analyzed separately exhibited lower DNA yields and consequently fewer loci exhibiting genotypes. Those cases whose swabs were analyzed collectively exhibited higher DNA yields and consequently greater numbers of loci exhibiting genotypes. These findings demonstrate that collective swabbings result in more complete profiles and lead to the recommendation that a firearm be swabbed in its entirety using no more than two swabs.     

Injuries due to deliberate violence in areas of Argentina. II. Lesions. Copenhagen Study Group

As part of a transcultural investigation of violent behavior in Argentina and Denmark, the lesions from accidents involving deliberate violence registered in the emergency wards of Hospital Fernandez and Hospital Pinero in Capital Federal Buenos Aires over a period of 13 and 17 months, respectively, were studied. Among the 281 victims entering the two emergency wards blunt violence without use of instruments was most often reported to be the violation method. Frequently indicated violation instruments against the male victims were batons (18.7%), sharp instruments (17.7%), and firearms (17.7%), the corresponding figures for female victims being 9.6%, 8.4% and 4.8%. The use of firearms and batons was considerably more pronounced in Argentina than in Denmark, particularly against male victims. A total of 373 primary and secondary diagnoses were reported from the patients, the most frequent diagnoses being contusions and open wounds in the head/neck region. Forty-three percent of the diagnoses were related to the head/neck region, being the most frequently injured region and the trunk the second most frequently injured region (30%). The degree of predominance of lesions in the head/neck region was much less than in the Danish material. Injuries of internal organs of the trunk were considerably more frequent in Argentina than in Denmark. Eighty-five percent of the victims had moderate or less serious lesions when assessed on the basis of the scores in the Abbreviated Injury Scale (AIS), (score less than or equal to 2). The AIS scores of the lesions in female victims were on average only slightly higher than those recorded in the Danish study, while 16.1% of the male Argentinian victims had lesions scored greater than or equal to 3 compared to 1.8% in male Danish victims. The need for treatment and hospitalization was more pronounced than in the Danish study. It may be concluded that the frequency of serious cases of deliberate violence probably would decrease if more restrictive rules for the possessing of firearms were enacted and enforced.     

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.     

A method for collection of gunshot residues from skin and other surfaces

A method of collecting gunshot residues from the skin of persons who have been injured by firearms has been developed. The method uses a commercially available, adhesive, transparent plastic film. This method is also useful for collecting gunshot residues from other objects, such as leather. The shooting distance is later estimated by ocular, microscopic or IR examination in combination with various chemographic tests.     

Handmade Guns in Trabzon, Turkey

Abstract:  A wide variety of handmade firearms have been involved in criminal cases in the city of Trabzon, Turkey. Although they are often very similar to commercially manufactured firearms in terms of design, loading and locking mechanisms, and cocking and firing arrangements, these guns are constructed from cheap materials and are not safe for firing. Handmade firearms manufactured in the Black Sea region of Turkey, particularly in the city of Trabzon, are similar to pistols manufactured by Browning, Luger, Star, Smith and Wesson, Berretta, and MAB. A total of 201 handmade guns referred to the Criminal Police Laboratories for examination from 2003 to 2005 were evaluated with respect to type, number of barrels, size and caliber, rifling, design, mechanism, operability, legality, and similarity to commercial models. We found that most of these handmade guns resembled commercial models in several aspects.     

Distribution of gunshot residues--the influence of weapon type

Gunshot residue (GSR) analysis is a frequently used forensic method for investigating shooting events. In this process, GSR-particles are detected on pertinent objects, often the hands of a suspect, with energy dispersive X-ray microanalysis in a scanning electron microscope. The question asked in court is usually the following: "… has or has not a given shot been fired by the suspect (at a certain place and time)?" Unfortunately, this question frequently cannot be answered by the analyst. Only the presence or absence of "characteristic" GSR-particles on the investigated sample can be stated with confidence. All other assumptions are inherently biased by many factors that are usually only known by the culprit or are generally unknown. In order to draw more profound conclusions from GSR analytical results, the dynamics of GSR particles have to be considered, i.e., how these particles reach a suspect. Consequently, the formation of the plume after firing was investigated for eleven different firearms with high speed-video analysis. The results show that a vast scope exists between revolvers - distributing many particles near the shooter - and e.g. shotguns that are quite sealed. These differences between the various weapon types should be considered for interpretation of the results of GSR-analysis.     

Prevalence of organic gunshot residues in police vehicles

The present study investigated the organic gunshot residue (OGSR) background level of police vehicles in Switzerland. Specimens from 64 vehicles belonging to two regional police services were collected and analysed by LC-MS in positive mode. The driver’s and back seats were sampled separately to monitor potential differences between locations and to assess the risks of a suspect being contaminated by OGSR during transportation to a police station.The results showed that most of the 64 vehicles were uncontaminated (44 driver’s seats and 38 back seats respectively). Up to six of the seven targeted compounds were detected in a single sample, once on a driver’s seat and twice on back seats. The contamination frequency generally decreased as the number of compounds detected together increased. The amounts detected were in the low ng range and less than amounts generally detected just after discharge on a shooter. Our data indicated that detecting a combination of four or more compounds on a police vehicle seat appears to be a relatively rare occurrence. The background contamination observed was most probably due to secondary transfer from police officers (e.g. through recent participation in a shooting session or firearm manipulation) or from firearms stored in the vehicles. The present results might be used as a recommendation to minimize contact of a suspect with contaminated surfaces if OGSR is implemented in routine work in parallel to IGSR analysis.     

Mandibular fracture caused by absolute close-range gunshot with a blank cartridge fright weapon]

Bony injuries caused by starter's pistols were repeatedly observed in the form of fractures of the temporal squama and other thin osseous lamellae; in experiments rib fractures could also be produced. In the presented case a contact shot from a blank cartridge pistol caused a fracture of the lower jaw (transverse fracture with a bone fragment split off in reg. 46). The friend of the 17-year-old victim had fired a shot to the right mandibular region during an argument. In the depth of the gunshot entrance wound, which communicated with the oral cavity, intense soot deposits were found as signs of the contact shot.     

Backspatter on the firearm and hand in experimental close-range gunshots to the head

The deposition of backspatter on the firearm or person shooting can greatly assist the reconstruction of shooting incidents. Backspatter was investigated in experimental transverse gunshots (9-mm Luger) to the heads of calves (n = 9) from shooting distances of 0 to 10 cm. The firearms were examined with a magnifying glass; the surgical gloves and the right sleeve worn by the person shooting were examined with a stereomicroscope. On the firearms, backspatter of blood was found in five of the nine cases, and one or both gloves showed bloodspatter deposits in six and the right sleeves in four cases. Most droplets were 1 to 3 mm and circular or elongated. In addition, a fine spray of tiny blood deposits was present on the firearm and textiles in four cases. The distribution of the droplets on the firearms varied: the areas included regions shielded by prominent parts, and the droplets were predominantly located on the extensor side of the fingers and the radial aspect of the hands and sleeves. Backspatter of tiny bone fragments was recovered from the firearm and sleeve in only one case, but tissue (bone, fat, muscle, skin) was present on the ground in front of the entrance wound in seven cases. A careful investigation, including appropriate lightning and magnification, is necessary for reliable statements concerning the absence of backspatter or the extent of backspatter present.     

Radiodense bullet wipe around osseous entrance gunshot wounds

“Bullet wipe” is the material deposited by a bullet on any surface with which it comes into contact after it is fired and may contain debris from the gun barrel, including particles of primer and metal fragments from previously fired bullets. X‐ray analysis is a non‐destructive method by which traces of metallic elements can be visually detected. The analysis of osseous defects for radiodense bullet wipe (RBW) assists in determining the presence or absence of perforating gunshot wounds, especially in fragmented, skeletonized remains. The aim of our current study was to determine the frequency of RBW around entrance firearms injuries that perforated bone. We prospectively analyzed entrance gunshot wounds for RBW over a three‐year period using digital X‐ray analysis (n = 59). We retrospectively reviewed the corresponding autopsy reports to determine the frequency of RBW by biologic sex, reported ancestry, age‐at‐death, location of wound, manner of death, range of fire, bullet caliber, and presence of bullet jacket. Data were analyzed by Fisher's exact test or Chi‐square test with significance levels accepted at p < 0.05. RBW was present in 66% (n = 39) of examined cases. Decedent characteristics did not significantly alter RBW distribution, including biologic sex (p = 0.75), reported ancestry (p = 0.49), and age‐at‐death (p = 0.43). Additionally, the location of the osseous entrance gunshot wound, manner of death, range of fire, and cartridge caliber did not affect RBW detection. All cases involving non‐jacketed rounds (n = 5) showed RBW (p = 0.30). To our knowledge, this study is the first to report the frequency of RBW detection from osseous entrance gunshot wounds.     

Indian homemade firearm--a technical review

A wide variety of homemade (country made) firearms are involved in crime cases in India. These firearms are made up of very cheap material and are not safe for firing. Moreover, the country made firearms are different in their design, loading and locking mechanism, cocking and firing arrangements. In this paper we have studied the characteristic features of 300 country made firearms received for examination in the Central Forensic Science Laboratory (CFSL), Chandigarh during last two decades. The characteristic features of these firearms are so unique that the fired crime bullets or cartridges can easily be matched with the test. It is hoped that such information will be useful for firearm experts in case of interpretation.     

Soft tissue radiography in determining contact and near-contact gunshot wounds.

Contact and near-contact gunshot wounds ordinarily show distinctive gunpowder patterns, muzzle imprints, or tearing of the skin. Microscopic and chemical examination have been used to estimate firing distances. A new method that utilizes soft tissue radiography is described. Nonjacketed lead bullets deposit a pattern of fragments and residues in tissue circumscribing contact and close gunshot wounds. Various patterns are presented to contrast the appearance of contact from distant gunshot wounds using various firearms and different types of bullets. This procedure may be used as an adjunct in the determination of contact and close gunshot wounds.     

Maggot-induced postmortem changes simulating gunshot wounds

In the warm season, human cadavers often are the breeding ground of fly larvae. In special conditions, the damage by maggots can take on the appearance of bullet holes. Preexisting injuries allow the maggots to penetrate the skin also in parts other than the body apertures commonly infested. Round tissue damage similar to gunshot-wounds are favored by the fact that the larvae of some types of flies bundle together to form feeding communities. The enzymes from the salivary glands of the fly larvae may in some rare instances even lead to perforation of bone lamellae (e.g. in the region of the orbital roofs). The case reports deal with 2 cases in which changes due to damage by maggots primarily gave the impression of gunshot-wounds.     

Reactivating deactivated firearms

Deactivating firearms necessitates a certain number of modifications to the firearm. We will show how in a number of cases these modifications were overcome. The material of which we dispose makes it possible to see what were the subsequent steps in the reactivation of the firearms. Inherently to their hand craft nature, very characteristic marks are obtained for the cartridge cases.     

Fatalities Caused by Spherical Bullets Fired from Blank Cartridge Guns in Istanbul, Turkey

Abstract:  Blank cartridge guns are generally regarded as being harmless and are not considered to be firearms in the legal sense in most countries. To show the danger of these guns upon simple modifications, we report 59 fatalities resulting from these simply modified blank cartridge guns in Istanbul, Turkey. The great majority of the victims were males and the age of those ranged from 11 to 61 years. In 55.9% of these cases, homicide was the origin followed by suicide (39%). The right temporal region was detected to be the preferred region in suicidal shots by blank cartridge guns with a frequency of 56.5%. In trial shots, all these guns were detected to discharge steel or lead spherical objects, generally 4 or 5 mm in diameter, successfully. Our findings strongly suggest that these guns should also be considered as handguns in the legal sense.     

Visualization of gunshot residue patterns on dark clothing

ABSTRACT: Determination of the muzzle‐to‐target distance is often a critical factor in criminal and civil investigations involving firearms. However, seeing and recording gunshot residue patterns can be difficult if the victim's clothing is dark and/or bloodstained. Trostle reported the use of infrared film for the detection of burn patterns. However, only after the film is developed are the results visible and multiple exposures at different settings may be needed. The Video Spectral Comparator^? 2000 (Foster & Freeman Ltd., Evesham, Worcestershire, U.K.) is an imaging instrument routinely used by forensic document examiners. Without use of specialized film could the VSC 2000 (at appropriate instrument settings) quickly, easily, and reliably provide instantaneous viewing, saving, and printing of gunshot residue patterns on dark and/or blood soaked clothing? At muzzle‐to‐target distances of 6, 12, and 18 in., test fires were made into five different types of dark clothing using eight different handguns of different calibers. Gunshot residues were detected for all eight calibers, and powder burn patterns were seen on dark clothing for all three target distances and calibers except 0.22 long rifle and 0.25 ACP. Bloodstains did not preclude the viewing of these patterns.     

The specificity of gunshot wounds caused by rubber buck shot

Described in the paper are forensic-medical cases related with examinations of wounds inflicted by rubber case-shot--a relatively rare ammunition. The morphology of the above wounds and specific features of deposition of "shot metals" in the damaged region were studied. The possibilities of fixing a shot distance and ammunition type were defined.