Fate and Behavior of Gunshot Residue: Recreational Shooter Vehicle Distribution

The susceptibility for recreational shooters to transfer gunshot residue (GSR) to both the interior and exterior of a vehicle is investigated. A comprehensive sampling protocol was used to assess the most likely areas of GSR transfer from recreational shooter contact, such as the steering wheel and the area, the firearms were stored (the trunk). Up to 315 characteristic GSR, particles were found in several locations throughout the interior of a vehicle. As many as 876 characteristic particles were found throughout a single vehicle. The data indicate that vehicles frequently occupied by firearms users are a potential source for inadvertent transfer of GSR to persons unrelated to firearm activity. In criminal cases where vehicles have been used, such transfer processes for GSR need to be considered within the context of any case interpretation. The implications for subsequent contamination and transfer processes from such vehicles require further investigation.     

Homemade Heavy Caliber Rifles—Two Unusual Firearms

Historically, in crimes involving heavy caliber rifles, only conventional factory‐made versions have been used. However, in recent years the number of homemade long‐barreled rifles is increasing. The characteristics of two such firearms that have been submitted to the Turkish Criminal Laboratory are discussed here. When the main parts of the guns were examined in detail, it was noted that nearly all of the parts had been made carelessly, with several structural defects visible. It was determined that the homemade heavy caliber rifles were unfit for efficient use and it was possible that they could have seriously harmed the shooter had they been fired. The development of these kinds of gun and the possibility of their use spreading throughout the country in terrorist attacks could cause a serious threat to national security.     

Secondary transfer of organic gunshot residues: Empirical data to assist the evaluation of three scenarios

The present study aimed at providing data to assess the secondary transfer of organic gunshot residues (OGSR). Three scenarios were evaluated in controlled conditions, namely displacing a firearm from point A to point B, a simple handshake and an arrest involving handcuffing on the ground. Specimens were collected from the firearm, the hands of the shooter and the non-shooter undergoing the secondary transfer in order to compare the amounts detected.Secondary transfer was observed for the three scenarios, but to a different extent. It was found that displacing a firearm resulted in secondary transfer in <50% of the experiments. The firearm also had an influence, as contrary to the pistol, no secondary OGSR were detected using the revolver. Shaking the hand of the shooter also transferred OGSR to the non-shooter's hand. In that case, the amount of OGSR was generally higher on the shooter than on the non-shooter. Finally, the largest secondary transfer was observed after the arrest with handcuffing with positive results in all cases using the pistol. In that scenario, the amounts on the shooter and the non-shooter were in the same range.This study highlights that the secondary transfer must be taken into account in the interpretation of OGSR. Indeed, an individual's hands might be contaminated by handling a firearm or having physical contact with a shooter.     

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.     

State background checks and firearms homicides

This study examined the relationship between state firearms homicides and background checks for firearms purchases. Controlling for economic and social conditions, the estimated number of firearms in circulation, offenders under community supervision, and violent crime it was found that states with less stringent background checks on firearms purchases were significantly associated with firearms homicides. The large number of firearms circulating within the United States makes it likely that a motivated—but ineligible—person could obtain a firearm over the long-term in the secondary firearms market. Effective state background checks, however, may temporarily frustrate an unauthorized person from obtaining a firearm that, in turn, may contribute to lower firearms homicide rates. Implications for further research are examined.     

Irrationality,Liminality and the Demand for Illicit Firearms in the Balkans and the North Caucasus

Most conventional approaches to the study of arms trafficking are grounded on the assumption that people are rational and always seek the most cost-effective means to achieve a goal. This article discusses the illicit firearms markets in the Balkans and the North Caucasus—the regions in which trafficking of illicit firearms has been flourishing since the early 1990s. By studying the demand side of this illicit market, it provides some possible explanations as to why numerous arms reduction measures have had limited results. It argues that cultural attitudes, socio-political complexity and emotions could explain much of the “irrational” behavior of those demanding weapons in these regions. The article contributes to the scholarly debate on the applicability of the rational choice theory-inspired arms reduction policies in highly textured sociocultural contexts. It is an effort to construct multifaceted conceptualization of human choice that focuses not only on the functionality of firearms but also on their symbolic and situational meaning.     

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).     

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.     

Homicide by gunshot. An evaluation of 50 homicides with reference to gunshot wound site]

In this paper the homicides committed in the region of Ulm with firearms over a period of 17 years were studied. These included 50 deaths caused by gunshot wounds, 33 males and 17 females. Homicides by firearms accounted for 44 percent, which was slightly higher than in other German regions. Homicide victims were found in all age groups with a markedly higher number up to the 20th year and in the fourth decade of life. In most cases small arms were used, and in many cases multiple shots were fired primarily hitting the head and the left side of the trunk: but injuries in the region of the extremities were also seen.     

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.     

Once more unto the breech: the firearms evidence in the Sacco and Vanzetti case revisited: Part I

The Sacco and Vanzetti case has a timeless appeal. It raises trenchant issues of the fairness of a criminal trial in the face of the public's hue and cry. It is a sorry reminder that physical evidence must be closeted with care and punctiliously marked for later courtroom uses. Claims of unfairness at the trial of Sacco and Vanzetti have evoked doubts of their guilt. On this issue, a Select Committee of firearms experts in 1983 reevaluated the existing firearms evidence from the Sacco and Vanzetti trial. Its conclusions, a number of which point unerringly to the guilt of Sacco and none of which add a scintilla to the case against Vanzetti, are analyzed in this paper, which is in two parts. Part I sets the stage by focussing on the facts of the crime in South Braintree, MA and the prosecutorial strategies in the use of the firearms evidence at the trial in Dedham, MA. The firearms evidence against Vanzetti is analyzed separately from that marshalled against Sacco. Part II will address the rampant charges of governmental misconduct in the handling of the firearms evidence. A concluding section of Part II reveals startling new evidence relevant to the guilt of Nicola Sacco.     

Particle Analysis for the Detection of Gunshot Residue (GSR) in Nasal Samples Using Scanning Laser Ablation and Inductively Coupled Plasma-Mass Spectrometry (SLA-ICPMS)

Currently, aluminum stub with carbon adhesive devices are used to collect inorganic gunshot residues (GSR) from the hands of a shooter. In an ideal shooting case, the gunshot particles do not persist for more than 2 h in the hands of the shooter, provided that the hands have not been washed. However, for forensic analysis and inference, the extended persistence of GSR would be desirable. This study investigates a novel GSR sampling and detection protocol. Sampling was performed in the nostrils using swab devices impregnated in ethylenediaminetetraacetic acid (EDTA). The GSRs persisted for longer periods in nasal mucus than on the hands, and particles were detected 6 h after shooting occurred. The analytical determination was conducted by scanning laser ablation-inductively coupled plasma-mass spectrometry (SLA-ICPMS) which enable the identification of the number of particles and their elemental composition. Seventeen isotope signals corresponding to ¹³C, ²⁰⁵Tl and 15 analytes that are usually associated with the composition of GSR residues were monitored: ²⁷Al, ²⁹Si, ³¹P, ³³S, ³⁵Cl, ³⁹K, ⁴⁴Ca, ⁵⁷Fe, ⁶⁰Ni, ⁶³Cu, ⁶⁶Zn, ¹¹⁸Sn, ¹²¹Sb, ¹³⁷Ba, and ²⁰⁸Pb. The SLA technique enabled the reduction of the swab analysis time to 40 min. The effectiveness of this methodology was evaluated with two types of firearms: a pistol and a shotgun. The results indicated that the methodology proposed for the analysis of the nasal GSR was effective and that it can improve or complement the forensic analyses and inferences presented in a court.     

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.     

Major vascular neck injury from a handgun cartridge casing

We present a case from the Johannesburg General Hospital of a zone II low-velocity penetrating neck injury with involvement of the ipsilateral subclavian artery. When the "bullet" was retrieved, it was noted not to be an actual bullet but rather a cartridge casing. We speculate that this injury represents one of several possible misfiring scenarios from a homemade firearm. Injuries from homemade firearms are infrequent in the literature, and only one other similar case of a cartridge casing causing a penetrating injury was found. A brief review of homemade handheld firearms is offered.     

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.     

Form follows function: Applying photographic content analysis to forensic firearm identification

Drawing forensic conclusions from an image or a video is known as “photographic content analysis.” It involves the analysis of an image, as well as objects, actions, and events depicted in images or video. In recent years, photographic depictions of objects suspected as illegal firearms have substantially increased, appearing on CCTV surveillance footage, captured by mobile phones and shared on social media. However, the law in Israel states that a person can be charged with illegally possessing a firearm only if it can be proven that the object is capable of shooting with lethal bullet energy. This becomes more challenging in cases where the firearm was not physically seized, and the evidence exclusively consists of images and video. In this study, photographic content analysis was applied to images and video where objects suspected as commercial or improvised firearms had been depicted. An image and event sequence reconstruction video databases of both firearms and replicas were created in order to better define firearm-specific functional morphological features. We demonstrate that it is possible to classify an object as a firearm by analyzing the functional, and not only the esthetic, morphology in images and video. It is also shown that event sequence reconstruction in video may be used to infer that an object suspected as a firearm has the capacity to shoot by confirming the occurrence of a shooting act or shooting process. Thus, photographic content analysis may be used to forensically establish that an object depicted in an image or a video is a firearm by ruling out other known scenarios, and without physically seizing it.     

Defending the scientific foundations of the firearms and tool mark identification discipline: responding to recent challenges

Recent challenges have brought the discipline of firearms and tool mark identification to the forefront in recent court cases. This article reviews those challenges and offers substantial support for the scientific foundations of the firearms and tool mark identification discipline. A careful review of the available literature has revealed that firearms and tool mark identification is rooted in firm scientific foundations, critically studied according to the precepts of the scientific method culminating in the Association of Firearms and Toolmark Examiners' Theory of Identification. Firearms and tool mark identification has been validated in a manner appropriate for evidence of the kind to be expected in firearms and tool mark examinations. Proficiency tests and error rates have been studied and can provide consumers of the disciple with a useful guide as to the frequency with which misidentifications are reported in the community using appropriate methodologies and controls. As a result, the primary issues in recent challenges do not invalidate the firearms and tool mark discipline as a science nor should it detract it from its admissibility in a court of law.     

Application of lead isotope analysis in shooting incident investigations

A study was conducted to examine the potential of the considerable variability of the lead isotope compositions in bullets (projectiles) and primers in shooting incident investigations. Multiple-collector inductively coupled plasma mass spectrometry (MC-ICP/MS) was used to analyze lead isotopic compositions in projectiles, cartridge cases, firearms discharge residues (FDR) in barrels of firearms and in the gunshot entries. .22 caliber plain lead and plated ammunition and 9 mm Luger full metal jacket (FMJ) ammunition were employed in shooting experiments using semiautomatic pistols. Cotton cloth served as the target material and two firing distances were tested; 1 cm (near contact) and 2 m distances. It was observed that various mechanical or chemical means of cleaning do not completely remove lead deposits ("lead memory") from barrels of firearms. Nonetheless, it was shown that analysis of lead isotopic composition may provide valuable evidence in investigating specific scenarios of shooting incidents. For instance in a shoot-out where several firearms and ammunition brands are involved, it may be feasible to point out which ammunition and/or firearm caused a particular gunshot entry if the ammunition brands involved (bullets and primers) differ considerably in their lead isotopic composition.     

Using polychromatic X-radiography to examine realistic imitation firearms

Sections 36-41 of the Violent Crimes Reduction Act (2006), which came into force in England and Wales on 1st October 2007, have placed significant restrictions on the sale and possession of 'realistic imitation firearms'. This legislation attempts to produce a definition of a 'realistic imitation' which clearly differentiates these items from other imitation firearms (which are not covered by the legislation). This paper will go a stage further by demonstrating techniques by which blank firing realistic imitation firearms which may be suitable for illegal conversion to fire live rounds may be differentiated from other less 'suitable' (but visually identical) realistic imitations. The article reports on the use of X-radiography, utilizing the bremsstrahlung of a commercial broad spectrum X-ray source, to identify the differences between alloys constituting the barrels of distinct replica and/or blank firing handguns. The resulting pseudo-signatures are transmission spectra over a range from 20 to 75 kV, taken at 1 kV intervals, which are extracted from stacks of registered, field flattened images. It is shown that it is possible to quantify differences between transmission spectra for components of different realistic imitation fire arms, and apply the results to determine the suitability of particular gun barrels from blank firing imitation firearms for illegal conversion to fire live rounds, or related illegal modifications.     

Fatal firearm accidents in Sweden

According to Swedish law, it is prohibited to possess and use firearms without a special permission (license), which is given only after a detailed personal investigation. This restrictive legislation accounts for the fact that deaths due to firearms in Sweden are rare in an international comparison. The number of accidental firearm fatalities in Sweden is 0.074/100,000 living persons. We have previously published a series of accidental firearm fatalities during hunting, and now we present an investigation on the non-hunting fatalities. The mean age of the victims was 27 years, and males predominated. Handguns, military rifles, and shotguns caused most of the accidents. The first published case of fatal thoracic airgun wound is also included. Slightly more than half of the accidents were caused by another person and were inflicted at close range. Unsafe handling of the guns, especially "playing" with the gun or during military training caused most of the accidents. It is doubtful that one could further decrease the low number of fatal firearm accidents in Sweden by even more restrictive legislation. Instead, it is concluded that the most important factor to stress is the safer handling of weapons.