Investigation of the variability in the tool marks produced by modified blank firing pistols on fired 7.65 mm projectiles

Firearms identification has an important place in forensic ballistic investigations since the weapons are widely used in criminal offences. Firearm examiners resolve many case files, through the use of automatic systems or comparison microscopes. Advanced forensic technologies like BALİSTİKA helps to record and analyze non standard ballistic evidence. In today's world, with the ease of access to materials and production technique information, pistols modified from blank firers are frequently encountered as crime tools. In this study, the characteristics of 7.65 mm fired cartridge cases obtained by controlled shots from blank firing modified pistols were examined, and their detection performances were compared by means of the Balistika system. Although distinctive differences are not expected after successive test shootings, balistically important changes were seen after the use of blank firing modified pistols and the 3D imaging system proved to be useful in observing such differences. The analyses showed that the modifications in weapons lead to variation in the ballistic characteristics and reduce the accuracy of the detection performance, which may result in flawed forensic decisions. It was also found that the deviations in ballistic impressions of modified blank firing pistols were greater than that of standard fabricated and hand-made pistols. This unique study contributed to the forensic sciences literature by focusing on the impact of modified weapons on ballistic characteristics.     

A singular case of murder-suicide committed with a homemade firearm

The authors illustrate a peculiar case of murder-suicide committed with a homemade firearm loaded with 12-gauge cartridges (buckshot). The structure and function of this handcrafted firearm were simple but effective: an iron tube did duty as a barrel in this primitive firearm. The cartridges (modified by winding sticky tape around the external surface of the base) were inserted down one end of the tube (serving as the breech). A second iron tube with a larger diameter (so as to be able to run over each of the preloaded barrels) and with a jutting, cone-shaped metal wedge soldered to the base, was used as a rudimental firing pin. After loading the "barrel" with the modified cartridge, the gunman would ram the "firing pin" tube violently down to fire the shot. Autopsy of the woman's body showed the presence of 3 gunshot wounds caused by buckshot, while the man had a single buckshot wound in the head. Subsequent ballistic investigations enabled reconstruction of the event (typical of murder-suicide) and the functioning of the firearm, demonstrating its lethal nature, remarkably easy handling, and simplicity of production.     

Fatal neck injuries caused by blank cartridges.

We report three cases where fatal neck injuries were caused by blanks from starting pistols. The weapons were loaded with blank cartridges or tear gas cartridges. Neither live ammunition nor any form of projectile was used. All three cases involved a contact discharge. The gas pressure caused by firing the weapons created extensive wound cavities in all three cases. Each victim died from blood loss as a result of ruptured cervical vessels; there were no air embolisms. In one case, a man shot himself eight times with two different starting pistols, and the wounds could be matched to each gun by the muzzle imprint marks on the neck.     

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.     

Reference ballistic imaging database performance

Ballistic imaging databases allow law enforcement to link recovered cartridge cases to other crime scenes and to firearms. The success of these databases has led many to propose that all firearms in circulation be entered into a reference ballistic image database (RBID). To assess the performance of an RBID, we fired 4200 cartridge cases from 600 9 mm Para Sig Sauer model P226 series pistols. Each pistol fired two Remington cartridges, one of which was imaged in the RBID, and five additional cartridges, consisting of Federal, Speer, Winchester, Wolf, and CCI brands. Randomly selected samples from the second series of Remington cartridge cases and from the five additional brands were then correlated against the RBID. Of the 32 cartridges of the same make correlated against the RBID, 72% ranked in the top 10 positions. Likewise, of the 160 cartridges of the five different brands correlated against the database, 21% ranked in the top 10 positions. Generally, the ranking position increased as the size of the RBID increased. We obtained similar results when we expanded the RBID to include firearms with the same class characteristics for breech face marks, firing pin impressions, and extractor marks. The results of our six queries against the RBID indicate that a reference ballistics image database of new guns is currently fraught with too many difficulties to be an effective and efficient law enforcement tool.     

Reference ballistic imaging database performance

Ballistic imaging databases allow law enforcement to link recovered cartridge cases to other crime scenes and to firearms. The success of these databases has led many to propose that all firearms in circulation be entered into a reference ballistic image database (RBID). To assess the performance of an RBID, we fired 4200 cartridge cases from 600 9mm Para Sig Sauer model P226 series pistols. Each pistol fired two Remington cartridges, one of which was imaged in the RBID, and five additional cartridges, consisting of Federal, Speer, Winchester, Wolf, and CCI brands. Randomly selected samples from the second series of Remington cartridge cases and from the five additional brands were then correlated against the RBID. Of the 32 cartridges of the same make correlated against the RBID, 72% ranked in the top 10 positions. Likewise, of the 160 cartridges of the five different brands correlated against the database, 21% ranked in the top 10 positions. Generally, the ranking position increased as the size of the RBID increased. We obtained similar results when we expanded the RBID to include firearms with the same class characteristics for breech face marks, firing pin impressions, and extractor marks. The results of our six queries against the RBID indicate that a reference ballistics image database of new guns is currently fraught with too many difficulties to be an effective and efficient law enforcement tool.     

Comparison of the Class and Individual Characteristics of Turkish 7.65 mm Browning/.32 Automatic Caliber Self‐Loading Pistols with Consecutive Serial Numbers

Abstract: Firearms identification is based on the fundamental principle that it is impossible to manufacture two identical items at the microscopic level. As firearm manufacturing technologies and quality assurance are improving, it is necessary to continually challenge this principle. In this study, two different makes of 7.65 mm Browning/.32 Automatic caliber self‐loading pistols of Turkish manufacture were selected and examined. Ten pistols with consecutive serial numbers were examined and each fired 10 times. The fired cartridge cases were recovered for comparison purposes. It was found that for each make of pistol, the individual characteristics within the firing pin impression, ejector, and breech face marks of all 10 pistols were found to be significantly different.     

Once again: risk of injury caused by blank pistols

The nature and extent of the use of blank pistols in Hamburg (according to the Hamburg crime statistics about 300 to 400 such cases per year; 34 cases involving head and neck wounds from 1989 to 1999 were investigated at our institute; among these 8 suicides, no homicide) as well as patterns of injuries caused by close distance blank pistol shots were analysed. 7 of these cases are described in detail. The results of our studies corroborate the warning statements made by many criminological and medico-legal experts regarding the danger inherent in these allegedly harmless weapons. Blank cartridge pistols can, when shot from a close distance, cause most severe injuries involving penetration into body cavities and bodily organs (especially in the head and neck), and even perforation of the skull. Therefore, we call for a much stricter control of weapons of this kind.     

Suicidal shot in the mouth with an unmodified blank cartridge pistol

In the medicolegal literature reports of suicides with weapons designed for self-defence, especially gas pistols, are rare. We report on a suicide of a 54-year-old woman who fired a fatal shot in her mouth with an unmanipulated blank cartridge pistol, make R?hm RG 8, calibre 8 mm. The autopsy findings (lips and mucosa of the buccal vestibule without injuries, but extensive lesions of the tongue and the middle and rear third of the smooth palate) suggest that the shot was fired - as observed by a witness - with the barrel of the weapon inside the oral cavity. Both macroscopic inspection and histological investigations excluded the possibility that death was caused by an injury of the brain, in particular the brain stem. The immediate cause of death was deep aspiration of chyme with concurrent aspiration of blood.     

Investigation of Ballistic Evidence through an Automatic Image Analysis and Identification System

Automated firearms identification (AFI) systems contribute to shedding light on criminal events by comparison between different pieces of evidence on cartridge cases and bullets and by matching similar ones that were fired from the same firearm. Ballistic evidence can be rapidly analyzed and classified by means of an automatic image analysis and identification system. In addition, it can be used to narrow the range of possible matching evidence. In this study conducted on the cartridges ejected from the examined pistol, three imaging areas, namely the firing pin impression, capsule traces, and the intersection of these traces, were compared automatically using the image analysis and identification system through the correlation ranking method to determine the numeric values that indicate the significance of the similarities. These numerical features that signify the similarities and differences between pistol makes and models can be used in groupings to make a distinction between makes and models of pistols.     

An Unplanned Complex Suicide by Multiple Blank Cartridge Gunshots and Cutting

Blank firing guns are readily accessible in most countries due to an absence of legal regulations. These weapons are capable of causing lethal injuries. We report a rare case of secondary (unplanned) complex suicide committed with a knife and blank cartridge pistol. A 59‐year‐old man was found dead with three superficial incisions in his neck and a gunshot wound to the chest. The external examination revealed an entrance wound in the left chest region consistent with contact shooting. The appearance of a muzzle imprint suggested two discharges. The autopsy showed a slightly hemorrhaged but otherwise intact pericardium, blood in the pericardial sac, and a channel‐like defect in the anterior wall of the left cardiac ventricle. The cause of death was attributed to cardiac tamponade. To the best of our knowledge, this is the first reported case of unplanned complex suicide involving an unmodified blank firing gun.     

Time since discharge of pistols and revolvers

The estimation of time since the latest discharge of pistols and revolvers has been achieved by the Solid Phase Microextraction (SPME) sampling technique and the GC/TEA analytical system. The TEA2 compound, which in our previous work (1) was observed in barrels of shotguns and rifles as well as inside spent cartridges, was also detected in pistols and revolvers. The amount of this compound was very low in short-barreled small arms and its escape from the barrel could generally be measured for only a few days or up to two weeks after the latest discharge. To improve the detection of TEA2 compound, the SPME sampling time was prolonged and fibers coated by Carboxen/polydimethylsiloxane were used. The decrease of the TEA2 peak with time after shooting from pistols is nonexponential but the curve-fitting procedure proposed for the estimation of time since discharge of shotguns and rifles is difficult to apply as the decay is very rapid. Therefore, the detection of TEA2 compounds in small arms should be interpreted that the firearm had been used very recently. The amount of volatile decomposition products of smokeless powder increased significantly with the length of the barrel when firearms of the same caliber, but with different barrel lengths were investigated.     

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.     

Magazine Influence on Cartridge Case Ejection Patterns with Glock Pistols

In this study, the cartridge case ejection patterns of six different Glock model pistols (one specimen per model) were compared under three conditions: firing with a loaded magazine, an empty magazine, and without magazine. The distances, covered by the ejected cartridge cases given these three conditions, were compared for each of the six models. A significant difference was found between the groups of data for each of the tested specimens. This indicates that it is important that, to reconstruct a shooting scene incident based on the ejection patterns of a pistol, test shots are fired with the same pistol type and under the correct magazine condition.     

Classification of firing pin impressions using HOG-SVM

Crimes, such as robbery and murder, often involve firearms. In order to assist with the investigation into the crime, firearm examiners are asked to determine whether cartridge cases found at a crime scene had been fired from a suspect's firearm. This examination is based on a comparison of the marks left on the surfaces of cartridge cases. Firing pin impressions can be one of the most commonly used of these marks. In this study, a total of nine Ruger model 10/22 semiautomatic rifles were used. Fifty cartridges were fired from each rifle. The cartridge cases were collected, and each firing pin impression was then cast and photographed using a comparison microscope. In this paper, we will describe how one may use a computer vision algorithm, the Histogram of Orientated Gradient (HOG), and a machine learning method, Support Vector Machines (SVMs), to classify images of firing pin impressions. Our method achieved a reasonably high accuracy at 93%. This can be used to associate a firearm with a cartridge case recovered from a scene. We also compared our method with other feature extraction algorithms. The comparison results showed that the HOG-SVM method had the highest performance in this classification task.     

Is the exploding powder gas of the propellant from blank cartridges sterile?

Shots from blank weapons loaded with blank cartridges, when fired from close range or as a contact shot, almost always cause the skin to burst open and lead to injuries to structures below the surface. Subsequently, wound infections are often observed. In addition to the introduction of skin germs, the possibility exists that contaminated propellants may enter into consideration as a source of infection. Using step-by-step experimental procedures we were able to demonstrate that: 1. Blank cartridge propellants were almost always contaminated with Bacillus cereus (nitrocellulose powder more so than black powder); 2. When the shot is fired numerous bacteria survive and are forced out with the gunsmoke from the weapon and thus find their way into the wound. In principle, blank cartridge propellant thus exhibits as much potential for wound infection as the skin germs. Clearly, the species B. cereus is prominent in this context. For open injuries even with ‘harmless’ blank weapons, an antibiotic prophylaxis should always be administered.     

Planned complex suicide by self-poisoning and a manipulated blank revolver: remarkable findings due to multiple gunshot wounds and self-made wooden projectiles

A remarkable case of complex suicide with poisoning and multiple self-inflicted gunshot wounds to the head is reported. After ingestion of a liquid insecticide, the victim shot himself twice in the head, once in each temple. Self-manufactured wooden dowels were used as projectiles in combination with conventional blank cartridges. The dowels had been glued on top of the blank cartridges and expelled by propellant gases. Moreover, the blank revolver used had been extensively manipulated in a rarely observed manner. Several occlusive devices had been removed from the barrel and the cylinder chamber to enable the expulsion of the wooden projectiles. The investigation of the methods used and the circumstances found at the scene pointed towards a planned complex suicide. A remarkable case with unusual projectiles, i.e., wooden dowels, fired by an extensively manipulated blank gun is reported, emphasizing the importance of close collaboration between the police firearm laboratory and forensic pathology in practical casework.     

Development of STR profiles from firearms and fired cartridge cases

Fired cartridge cases are a common type of evidence found at crime scenes. However, due to the high chamber temperatures and touch nature of this evidence, DNA testing is not commonly sought because it is believed DNA is only present in low levels, whether it is due to initial low levels of DNA and/or DNA degradation from the heat or inhibition of the PCR reaction. Moreover, very few laboratories report STR typing success with fired cases. This study focused on obtaining STR profiles from fired cartridge cases using the AmpFℓSTR^® MiniFiler™ kit, which is designed to amplify DNA from low level, inhibited, and degraded samples. Comparisons to other STR amplification kits were also conducted. In attempt to simulate casework, random individuals loaded cartridges into a firearm. DNA was recovered from the fired cartridge cases using the double swab technique and extracted using an automated large volume DNA IQ™ method. Initially, testing focused on known shedders handling cartridges for 30 s prior to firing. A significantly greater number of alleles was obtained following amplification with the MiniFiler™ kit versus the PowerPlex^® 16 BIO kit. No alleles were observed using the Identifiler^® kit. In an attempt to better simulate casework, a random selection of laboratory personnel handled shotshells for as long as needed to load and fire the weapon. In this mock sample study, the MiniFiler™ kit successfully amplified an average of 22% of expected alleles from DNA recovered from shotshell cases versus the PowerPlex^® 16 BIO kit where an average of 7% of alleles were observed. However, the total number of alleles obtained from the two kits was not significantly different. The quality of the DNA obtained from fired cases was studied with evidence of inhibition in at least 11% of shotshell case samples. After swabbing the head and the hull of three shotshell cases separately, a significantly greater number of alleles was obtained from the hull as opposed to the head of the fired shotshell case. In addition, after firing, various internal firearm surfaces were swabbed, including the chamber of barrel, ejection port, and breechface, in an attempt to obtain amplifiable DNA. DNA was obtained from the chamber of the barrel and was amplifiable using the MiniFiler™ kit, although mixtures were obtained with extensive drop-in and drop-out making this analysis unlikely to aid an investigation.     

Performance Evaluation of a Registered Ballistic Database Using the Evofinder® System

Firearms for police in China are registered along with their fired bullets and cartridge cases. A Registered Ballistic Database (RBD) of 1000 Norinco QSZ‐92 pistols with registered ammunition was established and was evaluated through the Evofinder® system. In this research, 1000 bullets and 1000 cartridge cases were randomly selected and correlated against an RBD of 2996 bullets and 2999 cartridge cases. Examiners found that successful identifications all ranked 1st, supported with land (100%), groove (97%) engraved areas, and primary marks (85.6%) for bullets, and firing pin impressions (99.8%), and breech face marks (99.9%) for cartridge cases. Two known matches (KM) for the same pistol rank in the top two (100%). The distribution of similarity scores varies from marks; however, the Evofinder® system could still effectively distinguish known matches from known nonmatches (KNM) for either bullets or cartridge cases. This study demonstrates the efficiency of the RBD.     

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.