The systemic error in the vertical component of handgun bullet trajectory reconstructions

Establishing the path or trajectory of a fired bullet is an often recurring part of shooting incident reconstruction. The current study describes how gravitational pull causes a systemic error on the vertical component of a trajectory reconstruction. Bullet drop, drop angle, and vertical offset are explained and calculated for 10 different handgun/ammunition combinations over a range of distances up to 100 m. The presented results are intended to provide forensic firearm examiners with a reference frame for the magnitude of error introduced on handgun bullet trajectory reconstructions over distance. Threshold values of 20 and 30 m are proposed as conservative distances up to where bullet trajectories can be modeled as straight lines with subsonic/transonic handgun bullets and with supersonic handgun bullets respectively. Both the bullet drop and vertical offset will be below 5 cm at these distances for those categories. The drop angle will be below 0.3°.     

Discordance of Gross and Histologic Findings in Estimating the Range of Fire of Gunshot Wounds

Forensic pathologist use soot and/or stippling surrounding entrance gunshot wounds in categorizing range of fire. If absent, some pathologists suggest utilizing histology when the range is diagnostically critical. This study investigates the concordance of macroscopic and microscopic findings in estimating range of fire by evaluating gunshot entrance and exit wounds made through human tissue analogs at defined distances using two handgun calibers. Examination of over 150 entrance wounds verified the ease of visually detecting soot from a muzzle distance of contact to 1 foot (30.5 cm), and its absence at 9 feet (274.3 cm). Distinctly apparent was bullet wipe surrounding the entrance wounds regardless of muzzle distance. Although variations existed, dark material was histologically identified in many skin, soft tissue, and bone sections at all ranges with both calibers. These nonparallel results decrease the dependability of histology for range of fire estimation and reinforce using gross observation.     

Suicide by Close-Range Gunshot Wound to the Bridge of the Nose

Suicidal gunshot wounds to the nasal bridge are rare, particularly at close range (defined as muzzle of the weapon not touching the skin surface, but near enough to deposit soot and stippling). Previously reported suicidal gunshot wounds to the nose have been through the left nostril (Forensic Sci Int 1995;71(1):25–31; J Forensic Radiol Imag 2013;1(2):63–7). The death of a 26-year-old man with a close-range gunshot wound to the bridge of the nose was deemed suicide due to history, scene, and autopsy findings. These findings included previous suicidal ideation, texted and written notes, the decedent's cross-legged position seated on the floor, the trajectory of the bullet through his head and into the ceiling fan and roof above him, and acute alcohol intoxication. This decedent may have been intending a hard contact forehead location but inadvertently fired the gun into the bridge of his nose while bending forward, prior to contact.     

Shots fired with silencers--a report on four cases and experimental testing

Four cases of homicide, in which silenced firearms were used, are reported and supplemented by data from experimental investigations regarding wound features, marks, traces, and ballistic behavior. Wound features are largely determined by the construction of the silencer. In one case, even a muzzle imprint was produced by a silenced weapon fired at contact range. In general, silencers are likely to result in a decrease in bullet energy and accelerated energy release in the target (tissue). In terms of wound morphology, silencers produced a reduction in or even a lack of the contact ring (ring of dirt). In close-range and contact wounds, any features indicative of shots fired at close range were missing (such as soot deposit and powder tattooing). It is also worth mentioning that biological matter may get into the silencer in shots fired at contact range.     

Suicidal single gunshot injury to the head: differences in site of entrance wound and direction of the bullet path between right- and left-handed--an autopsy study

The aim of this study was to determine the differences in the anatomical site of a gunshot entrance wound and the direction of the bullet path between right- and left-handed subjects who committed a suicide by a single gunshot injury to the head. The retrospective autopsy study was performed for a 10-year period, and it included selected cases of single suicidal gunshot head injury, committed by handguns. We considered only contact or near-contact wounds. The sample included 479 deceased, with average age 47.1 ± 19.1 years (range, 12-89 years): 432 males and 47 females, with 317 right-handed, 25 left-handed, and 137 subjects with unknown dominant hand. In our observed sample, most cases involved the right temple as the site of entrance gunshot wound (about 67%), followed by the mouth (16%), forehead (7%), left temple (6%), submental (2%), and parietal region (1%). The left temple, right temple, and forehead were the sites of the gunshot entrance wounds, which were the best predictors of the handedness of the deceased (Spearman ρ = 0.149, P = 0.006). Our study showed that the direction of the bullet intracranial path in cases of suicide was even a more potent predictor of the handedness of the deceased (Spearman ρ = 0.263, P = 0.000; Wald = 149.503, P = 0.000).     

Study of unusual phenomenon of contact firing on gelatine block using .38 Special revolver--forensic importance

Gunshot wounds in suicide cases are self-inflicted wounds. Self-inflicted wounds in suicide cases are usually caused by contact firing and are of great forensic significance. Evaluation of contact wound may be associated with difficulties if the bore gets obstruction prior to firing. This paper investigates the phenomenon and interprets the results of test firing conducted on 20% gelatine block at 10 degrees C, using .38 Special revolver with obstruction of a bullet in the bore. Test firings were conducted in three different muzzle-target contact conditions keeping the muzzle pressed against the gel block in each case. The physical evidence and the wound ballistic parameter namely bullet track, remaining velocity of the bullets and volume of permanent cavity have been studied. When compared with the results of contact firing conducted with the same firearm without having any bore obstruction under similar conditions, it has been found that the physical evidence and the wound ballistic parameters would be helpful for interpretation of such unusual incidents for forensic inference.     

Medicolegal aspects of witnessed suicide due to gunshot to the head. II. Legal medicine aspects and examination of the firing hand

The second part of the paper on suicides by gunshots to the head in the presence of witnesses focuses on relevant morphological autopsy findings such as entrance site, signs of close range or contact shots, bullet path etc. and also discusses selected aspects of ascertaining gunshot residues. For the identification of the shooter an integral medicolegal assessment of all the facts including the investigation results and the autopsy findings is essential. However, the morphological findings alone do not allow safe diagnosis, as for example in a homicide the temporal region, which was affected in all our cases, may have been deliberately chosen by the perpetrator as a localization typical of suicide. Thus methods to ascertain gunshot residues on the firing hand (by means of adhesive films and the polyvinyl-alcohol collection method--PVAL) are of great practical importance. In seven cases adhesive films and/or the polyvinyl-alcohol collection method were used. In one case the gunshot residues (GSR) were analysed by means of tape lifts and subsequent scanning electron microscopy (SEM). It was found that especially the combined application of topographical (adhesive tape/PVAL) and cumulative (SEM) methods allowed for the doubtless identification of the shooter, thus usually confirming the suicide. By the example of one case it is demonstrated that without the immediate collection of evidence at the scene objective reconstruction of the event becomes impossible. On the basis of the reported cases recommendations are finally given for a differentiated approach in the medicolegal evaluation of alleged witnessed suicide by gunshot (to the head).     

Influence of ballistic and autopsy parameters on the manner of death in case of long firearms fatalities

A retrospective study was carried out on 132 fatalities due to gunshot wounds secondary to long firearms. One group of suicide (n=72) and one group of homicide (n=60) were statistically compared regarding age and sex of the victim, number of shots, range of fire, direction of the projectile(s), anatomical distribution of entrance sites, weapon and ammunition types and the nature of eventual associated traumatic lesions. The frequency of suicide was higher when the victim's age increased. Females constituted about 43% of the homicide victims and about 8% of the suicide victims. 51.5% of the homicide victims and about 10% of the suicide victims had sustained more than one gunshot wound. Close range was respectively found in 53.5% of the homicide cases and in all suicide cases. Most of the suicide cases (85% of the cases) showed typical entrance sites. Entrance sites in the limbs and lateral or posterior wall of the chest were only encountered in homicide cases. Associated traumatic lesions were found in about 23% of the homicide cases and in 18% of the suicide cases. In case of suicidal gunshots to the left chest, both upwards and downwards directions, and also both right-to-left and left-to-right directions can occur. From 22 suicide cases showing entrance wound in the mouth, a downwards direction was found in only one. This study underlines the importance but also the limits of the autopsy findings (including direction of the projectile(s) related to the entrance site) for giving an indication of the manner of death (homicide vs. suicide).     

Influence of Muzzle Instability on Bullet Deflection after Perforating Laminated Particleboards

The influence of muzzle instability on bullet deflection, when perforating laminated particleboards, was studied with three different handgun bullet types. The mean deflection angles of .32 Auto FMJ and .38 Special SJHP bullets were calculated to be 0.90° and 0.83°, respectively after perforating particleboards orthogonally at a 1 m muzzle-to-target distance. The mean angles dropped to 0.70° and 0.58° at a 15 m muzzle-to-target distance. The differences in deflection angles proved to be statistically significant (p < 0.05) with p-values of 0.023 and 0.001, respectively. The mean calculated deflection angles of .38 Special LRN bullets also dropped from 1.51° to 1.38° when the muzzle-to-target distance was increased from 1 to 15 m, but this difference was not significant (p-value of 0.357). The results support the hypothesis that muzzle instability has an influence on deflection. The possible implications for shooting incident reconstructions and for future research are discussed.     

An unusual entrance wound associated with rimfire rifles.

In many cases of self-inflicted contact wounds of the head with rimfire rifles, we have noted that the entrance wound appears unusual: in 50% of cases studied, a pencil-like extension or zone of blackened and seared skin extends downward from the entrance. The most probable cause for the appearance of this wound is a momentary break in contact between the muzzle and skin as the victim reaches for the trigger with resultant escape of a jet of hot sooty gas. Whereas not unique for rimfire rifles, such a wound from a handgun is uncommon.     

Patterned imprint mark due to the folded shoulder stock: A possible finding in contact shots from submachine guns

The muzzle imprint (barrel mark) is a pressure abrasion typically associated with contact shots. Apart from the contours of the actual muzzle profile, other constructional parts such as the front sight and/or the recoil spring guide of semiautomatic pistols may be imprinted next to the bullet entrance wound. In some types of submachine guns the shoulder stock can be folded forward so that its end partly encircles the muzzle. If such a weapon was in contact with the skin at the instant of discharge, a corresponding contusion mark is to be expected. The imprint configuration may point to the type of weapon and to the way in which the gun had been held when firing the shot. The paper presents the injury pattern in a 36-year-old man who committed suicide with a Scorpion SA Vz 61 submachine gun cal. 7.65 mm Browning from former Czechoslovakia.     

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.     

Determined to Die! Ability to Act Following Multiple Self‐inflicted Gunshot Wounds to the Head. The Cook County Office of Medical Examiner Experience (2005–2012) and Review of Literature

Cases of multiple (considered 2+) self‐inflicted gunshot wounds are a rarity and require careful examination of the scene of occurrence; thorough consideration of the decedent's psychiatric, medical, and social histories; and accurate postmortem documentation of the gunshot wounds. We present a series of four cases of multiple self‐inflicted gunshot wounds to the head from the Cook County Medical Examiner's Office between 2005 and 2012 including the first case report of suicide involving eight gunshot wounds to the head. In addition, a review of the literature concerning multiple self‐inflicted gunshot wounds to the head is performed. The majority of reported cases document two gunshot entrance wound defects. Temporal regions are the most common affected regions (especially the right and left temples). Determining the capability to act following a gunshot wound to the head is necessary in crime scene reconstruction and in differentiation between homicide and suicide.     

Recent Firing Range Suicides in South Australia

Abstract: Two cases are reported from South Australia, where deaths occurred that were due to single self‐inflicted gunshot wounds to the head in individuals who were visiting indoor firearm ranges. Case 1: A 54‐year‐old man visiting an indoor firing range placed a .357 magnum handgun to his head and fired one shot. Case 2: A 23‐year‐old woman who was being instructed in firearm usage at an indoor firing range placed a 9 mm handgun to her head and fired one shot. In both cases, deaths were due to cerebral laceration with skull fracture. Firing ranges may be utilized by individuals who are seeking weapons for suicide attempts, and suicide may be successfully undertaken at such locations even while a victim is under direct supervision. In jurisdictions, where firearm ownership is strictly legislated, it may be that clubs can inadvertently provide access to firearms for this type of activity.     

Multivariate analysis ('forensiometrics')--a new tool in forensic medicine. Differentiation between firearm-related homicides and suicides.

A forensiometric model to discriminate between homicidal and suicidal firearm-fatalities is presented. It is based on a survey of all 45 homicidal and 251 suicidal firearm-fatalities that were examined at the Department of Forensic Medicine in Stockholm, Sweden during the period 1983-92. The model used 15 variables to describe 19.8% of the variation in the data and its goodness of prediction, Q2, was 0.742. The variables ranked in falling order of covariation with homicide (i.e. correlation with or importance in the prediction of homicide) were: presence of other injuries than firearm-wounds, entrance wound in the front part of the chest except precordium, bullet path through clothes, entrance wound in upper extremity, female victim, entrance wound in abdomen, entrance wound in head except temples, central forehead and mouth, and entrance wound in back. The variables most correlated to suicide were: used firearm found close to victim's body, reported suicidal ideation, victim's age, presence of contact wound(s), male victim, presence of farewell letter and entrance wound in mouth. The model was thereafter validated on a test-set of 18 homicides and 84 suicides during 1993-95. All suicides and 16 homicides were classified by the model in agreement with the previous police and forensic medical examinations. Thus, the model's sensitivity to classify homicides is estimated to be 89% and its specificity 100%.     

An atypical gunshot wound from a home-made zip gun--the value of a thorough scene investigation

Zip guns and the atypical gunshot wounds they produce are rare in forensic pathology. Because of this, investigators and forensic pathologists may be unfamiliar with their construction, appearance, and the wounds associated with them. A 43-year-old mechanic, with a history of depression was found dead in a washroom stall at work with an atypical gunshot wound of the head. Upon initial investigation, no weapon was found at the scene. Due to the nature of the scene, and the unusual characteristics of the wound, the manner of death was at first thought to be a homicide. Subsequently, a simple zip gun, which had been overlooked during the scene investigation, was discovered by a co-worker while he was cleaning the stall. Examination of the wound revealed evidence of contact range firing. A markedly deformed bullet was recovered from the head, consistent with the use of the home-made gun. These findings, along with further police investigation and review of the past medical history, indicated that the manner of death was a suicide.     

Fatalities from black powder percussion handguns

Three suicides and one homicide from black powder muzzle loading handguns are reported and the muzzle velocities of two weapons are recorded. The fatal head shots caused wide wound tracts traversing the brains and intracerebral haemorrhages remote from the tract were present in every case. The skulls showed considerable fractures which were pronounced in the cases of contact shots but were also present when the range of fire was 5 m. These extensive injuries from soft lead spheres with muzzle velocities of only ∼200 m/s are attributed to the expansion of the spheres. The regularly occurring deformation resulted in 13–16 mm calibre missiles in the cases of .44 spheres. The special features of black powder such as incomplete and slow combustion resulted in intense soot deposits in the vicinity of the entrance wound and in long ranges the gunshot residues travelled. In contact shots, large pocket-like underminings even in deeper tissue layers, abundant soot along the trajectory and skin burns were observed.     

An Unusual Case of Multiple‐Gunshot Suicide of an Alcohol‐Intoxicated Cancer Sufferer with Prolonged Physical Activity

Multishot firearm suicides are relatively rare and suggest the possibility of homicide. Physical activity following gunshots to the head, the neck, and the thorax does occur, and immediate incapacitation does not occur in every fatal gunshot wound that penetrates the head or perforates the heart. Cancer patients appear to be at increased suicide risk, but alcohol intoxication is less common in such cases. We present—to the best of our knowledge for the first time—a case of a 54‐year old, male, liver cancer sufferer, who under the influence of alcohol, discharged his revolver three times, suffered, among other wounds, a heart‐perforating wound, and died after c. 1.5 h, being able to talk until just before he died. Our case underlines the importance of keeping an open critical mind when dealing with multiple‐gunshot fatalities, especially when posttraumatic physical activity might be crucial in differentiating homicide from suicide.     

Distinguishing between homicide and suicide knots and ligatures: A comparative analysis of case and survey data

Distinguishing between suicide and homicide can be challenging owing to ambiguous and confusing case details. In particular, there is a paucity of useful information comparing homicide and suicide knots and ligatures in the literature. Multiple knot and ligature characteristics have not been recognized previously because complete and accurate information has been lacking. Ninety external tying cases (mainly homicide) and 56 cases involving self‐tying (mainly suicide) were reviewed to compare multiple knot and ligature characteristics. Additionally, 189 survey volunteers performed four standardized external tying tasks and two self‐tying tasks, yielding comparison data from more than 1500 knots. Using all available data, it was determined that the differences between external and self‐tying included types of knots, ligature configurations, ligature tensions, wrist gaps, wend lengths, knot access, external anchoring, and other indicators. These differences are presented in a proposed analysis checklist inspired by medical and psychiatric protocols. The checklist contains 14 potential characteristics for head and neck bindings, 14 potential characteristics for wrists and arms, nine ankle and leg characteristics, and four linkage details. The proposed checklist can be expanded and fine‐tuned as more data are accumulated. It offers experienced knot analysts an additional tool to assist in drawing conclusions, which then can be related to other case evidence by investigators.     

Gunshot residue patterns on skin in angled contact and near contact gunshot wounds

The goal of this study was the reproduction of shape and pattern of gunshot residues in near contact and contact gunshot wounds by a series of experimental gunshots on a skin and soft tissue model. The aim was to investigate the shape and direction of soot deposits with regard to the muzzle according to different muzzle-target angles, firing distances, type of ammunition and weapon and barrel length. Based on a review of the literature and on the results of the experiments the authors could make the following statements of gunshot residues in angled contact and close contact gunshot: (1) gunshot residues on the target surface can be differentiated in a "inner" and "outer powder soot zone"; (2) the outer powder soot zone is much less visible than the inner powder soot zone and may lack on human skin; (3) with increasing muzzle target distance both inner and outer powder soot halo increase in size and decrease in density; (4) in angled shots the inner powder soot halo shows an eccentric, elliptic shape which points towards the muzzle, regardless of ammunition, calibre and barrel length; (5) the outer powder soot points away from the muzzle in angled contact and close contact shots.