Effects of Decomposition on Gunshot Wound Characteristics: Under Cold Temperatures with No Insect Activity

Abstract:  Information on gunshot wound characteristics has been well documented; however, there is little documented information on the effects of decomposition or environmental conditions on gunshot wound characteristics. This study was conducted in order to determine if decomposition would obscure or alter the physical surface characteristics of gunshot wounds when exposed to a low temperature environment. The study was conducted from November 2005 to January 2006 in Nova Scotia, Canada in forested and exposed environments, with air temperatures between −10°C and +10°C. Pigs were used as human models and were shot six times each at three different ranges (contact, 2.5 cm, and 1.5 m). Gunshot wound characteristics persisted until the wounds were covered with ice and snow, after which changes were observed. The changes were recognized as being unique to the different ranges of gunshots and it was concluded that changes due to decomposition under the conditions tested would not affect the collection and interpretation of gunshot wound evidence.     

Concordance Rate for the Identification of Distant Entrance Gunshot Wounds of the Back by Experienced Forensic Pathologists Examining Only Images of Autopsies

The images of 66 gunshot entrance wounds with a defect on the back, a bullet in the body, hemorrhage along the wound track, and logical certainty that it was an entrance wound were collected from the files of a moderately busy medical examiner's office. Participants numbering 22 board‐certified forensic pathologists viewed a single digital archival image of each of the 66 entrance wounds randomly mixed with 74 presumptive exit wounds to determine whether they were entrance or exit wounds. The concordance rate for correctly identifying the 66 logically known entrance wounds was 82.8% with a range from 58% to 97%. This pilot study was conducted to provide an evidence‐based approach to the interpretation of the direction of gunshot wounds by reviewing pathologists with access only to archival photographs, and it is not a measure of the accuracy to distinguish entrance from exit wounds when given all of the circumstances.     

带消音器枪弹创的实验病理研究

使用国产7．62mm口径微声轻型冲锋枪，以不同距离射击实验动物，制成带消音器枪弹创，并使用国产7．62mm口径轻型冲锋枪作对照进行对比观察。结果表明：在接触和近距离射击时，带消音器枪弹刻与典型枪弹剑比较有明显不同；根据消音器的结构和原理，结合实验结果，建立了带消音器枪弹创的形态学特征及其诊断依据。为法医学检验鉴定提供了实验性资料。     

对纤维蛋白诊断生前伤的评价——45例枪弹创组织的MSB染色和扫描电镜对比观察

生活反应是诊断生前伤的主要根据.近二十年来,法医病理学在研究生前伤和死后伤的诊断中,采用了多种新兴技术,如扫描电镜技术、酶组织化学技术、酶标技术、电泳技术等,促使生前伤的诊断水平有明显提高.伤后存活1小时死亡者,大部分皆可获得明确诊断;立即死亡或在濒死期形成的损伤,由于生活反应甚微,或受腐败等     

Firearm Deaths by Law Enforcement

Abstract:  The use of deadly force during law enforcement is a matter that compels public scrutiny. There were 42 gunshot deaths caused by police over a 4-year period in New York City. The decedents' average age was 31 years and ranged from 17 to 64 years. There were 41 males and one female; and 26 Black, nine Hispanic, and seven White decedents. Ethanol and/or drugs of abuse were detected in 78% (31/40) of the decedents. The vast majority of shootings occurred with the police responding to a crime and 90% of the decedents were armed (26 handguns, six knives, one axe, one metal pipe, and one toy gun). Vehicles were used as weapons in two incidents. A total of 177 bullets struck the 42 decedents. Fourteen decedents sustained single gunshot wounds (GSWs), and the remainder had multiple GSWs ranging from 2 to 21. In the majority of the cases in this study, the number of GSWs of the body was three or fewer. Thirteen decedents had at least one GSW of the back or buttocks, accounting for 25 of the total 177 wounds, and four of the 13 had GSWs of only the back. With the exception of the upper extremities, GSWs of all locations were more likely to penetrate than perforate. Although these deaths may be high profile, the certification is typically straightforward and the cause (i.e., GSW) and manner of death (homicide) are readily apparent. Although police shootings in which the decedent was unarmed and/or sustained numerous GSWs are widely reported by the lay press, these types of shootings were not typical in our study.     

Macroscopic,Microscopic, and Chemical Assessment of Gunshot Lesions on Decomposed Pig Skin

Abstract: Very little literature exists on gunshot wounds on decomposed material. In this study, seven pig heads underwent a shooting test. Entrance wounds from the first head underwent neutron activation analysis (NAA) and histological testing immediately after the firing test; the other six heads were exposed to two different environments (open air and soil) and analyzed by radiochemical and histological tests every 15 days. Gunshot wounds in air maintained their morphological characteristics, and those in soil showed severe alteration after 5 weeks. Microscopic testing verified positive results for lead in all gunshot wounds in open air, whereas in most of those in soil lead could not be detected. Radiochemical analysis performed by NAA yielded for all gunshot wounds but one antimony quantities in the range of 0.07–13.89 μg. In conclusion, it may be possible to detect residues of antimony even in degraded tissues.     

Characteristics and Frequency of Chipping Effects in Near‐Contact Gunshot Wounds

The presence of “chipping” or “flaking” around the edges of gunshot entry wounds has been described among the characteristics of gunshot wounds in bone. In this study, the real frequency of such a peculiar feature was investigated. The presence of “chipping” was assessed on 22 gunshot wounds fired at a near‐contact range on bovine ribs with 9‐mm bullets. As controls, five samples were shot with a 3 cm range, and five from 40 cm. In 77% of cases shot at near‐contact range, a detachment of small fragments of the upper layers of bone was detected, mainly with a circumferential disposition, whereas this feature was lacking in control samples. The study demonstrated the frequency of “chipping” and that it may probably be due to a combined ballistic effect of impact of the bullet itself and expansion of gases. It may be thus considered indicative of close‐range shots.     

Gunshot residues on dry bone after decomposition-a pilot study

Abstract: Very little literature exists concerning radiochemical and microscopic analyses of gunshot wounds in decomposed material, and even less concerning skeletonized samples; the most advanced technologies may provide useful indications for the diagnosis of suspect lesions, especially if gunshot wounds are no longer recognizable. However, we know very little of the survival of gunshot residues (GSR) in skeletonized samples. This study examined nine gunshot wounds produced on pig heads which then underwent skeletonization for 4 years, and four gunshot entries on human heads from judicial cases which were then macerated to the bone in water; the samples underwent scanning electron microscopy coupled with energy dispersive X‐ray (SEM‐EDX) analysis. Positive results for GSR were observed only in four of the nine animal samples and in all four human samples. Among the human samples, two lesions showed Pb and Sb, one lesion only Pb, and one Pb, Sb, and Ba. This pilot study showed the survival of GSR in skeletal material and therefore the crucial importance of SEM‐EDX analyses on skeletonized material. Further studies are needed in order to ascertain the role of environmental modifications of GSR.     

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.     

Trends in Officer‐involved Firearm Deaths in Oklahoma from 2000 to 2015

The purpose of this study was to collect data and disseminate trends in officer‐involved firearm deaths in Oklahoma from 2000 to 2015. The Oklahoma Office of the Chief Medical Examiner (OCME) database was searched for civilian decedents with gunshot wounds inflicted by law enforcement officers and officer decedents with gunshot wounds inflicted by civilians. Five decedents were law enforcement officers, while 274 decedents were civilians. The number of civilian decedents throughout the study followed a quadratic trend. Civilian decedents were most commonly males (95%) between the ages of 20 and 39 (64%), had one or two gunshot wounds (46%), and had an increasing number of gunshot wounds over time. Postmortem toxicology testing most commonly detected ethanol, methamphetamine, cocaine, and PCP. Efforts toward increased tracking by various agencies and more scientific studies like this are needed to facilitate future analysis of trends in officer‐involved firearm deaths.     

The Erratic Behavior of Lesions in Burnt Bone

This study analyses depressed fractures (by blunt force trauma) and circular full‐thickness injuries (drill injuries and gunshot wounds) in charred bones. Fifty bovine ribs (total 104 lesions) were divided into three groups. The first group consisted in 20 depressed hammer‐produced fractures; in the second one, 60 round drill‐holes were produced (30 circular, 30 semicircular); in the third group, 12 fleshed and 12 skeletonized ribs were hit by 9‐mm bullets. Each specimen was carbonized in an electric oven up to 800°C. Morphological and metric analyses were performed before and after: morphological features were preserved, but depressed fractures showed an increase in their dimensions (p‐value < 0.05); the drilled holes shrunk (p‐value < 0.01); the charring cycle increased the number of fractures in samples with gunshot wounds differently in fleshed and defleshed ribs. This study showed the complex behavior of charred bone, for what concerns the interpretation of trauma and how caution should be applied.     

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.     

An anthropological analysis of gunshot wounds to the chest

This analysis of gunshot trauma to the bony thorax examines 87 handgun and rifle wounds from documented cases in an effort to corroborate an earlier report and to provide the forensic community with additional literature in this area. Specifically, this study tests whether the trauma signatures associated with gunshot wounds in the bony thorax are useful in determining the direction of fire. Because the ribs occupy a significant portion of the bony thorax, they are struck more frequently than other bones and, consequently, they are the focus of this report. This study confirmed that bullets can leave distinctive markers on ribs that indicate the direction of fire, including depressed fractures, bone fragments displaced in the direction of the bullet's path, and beveling. Although forensic anthropologists can determine the direction that a bullet was traveling when it struck a given rib, they cannot give a definitive statement about the number or sequence of gunshots without supporting soft tissue evidence.     

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.     

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.     

Fate and Behavior of Gunshot Residue—A Review

A review of the literature concerning the fate and behavior of gunshot residue (GSR) is presented. A number of concomitant parameters including firearm and ammunition type, plume and GSR material characteristics, travel distances, chemical composition and GSR morphology are critically discussed in relation to their effects on the distribution and deposition, transfer and persistence processes of GSR. The underlying mechanisms associated with such processes are also considered. Knowledge of these processes on GSR materials could provide valuable information concerning scene preservation and subsequent forensic sampling. The number of GSR particles deposited can vary significantly with each firearm discharge, highlighting the potential to produce distinctive data in each individual case. With the continual development and compositional changes of new ammunition types, further evaluation of the effect these processes may have on GSR evidence and their possible influence on the interpretation of the analytical results should be given due consideration.     

Frequency of bone lesions: an inadequate criterion for gunshot wound diagnosis in skeletal remains

A retrospective study was carried out on 130 fatalities due to gunshot wounds to determine whether the combined absence of bone damage and projectile in a skeleton is sufficient to eliminate a diagnosis of gunshot wound. Our findings showed that bone lesions were present in about 90% of the cases and were associated with intracorporeal projectile(s) in about 70% of the cases. The presence or absence of bone lesions seemed independent of the gun characteristics, the shot conditions, and the type of death. The cause of death was predominantly brain injury in cases with bone lesions whereas thoracic, abdominal, and peripheral vascular causes were more frequently encountered in cases without bone damage. We concluded that the combined absence of bone lesions and intracorporeal projectile (about 5% in our series) cannot exclude a diagnosis of death secondary to gunshot wounds.     

Suicide by Shotgun in Southeastern Minnesota

Suicide by shotgun is a common method of suicide with high regional variation. We sought to describe their distinct, challenging features and provide demographic and risk characteristics. We reviewed 228 gunshot wounds autopsied at Mayo Clinic from 1994 to 2014; of these, 75 (32.9%) were shotgun wounds. All were suicides and contact range. Ages ranged from 14 to 92 years old; of these, 97% were men. The majority involved the head (70.9%), were intraoral (48.2%), and had upward (73.2%) and backward (73.2%) directionality. Next most common was the chest (21.5%), with backward (94.1%) and downward (64.7%) directionality. Four involved multiple wounds. Wadding was recovered in 16 (21.3%) cases. Six (8.0%) had a survival period. Most (66.7%) took place at home. Seventy‐one percent had a known psychiatric history; 32.4% had positive toxicology. Although contact range shotgun wounds cause severe destruction, entrance wound and other characteristic are identifiable with thorough scene, autopsy, and radiographic documentation.     

Forensic Radiology Pitfalls: CT Imaging in Gunshot Wounds of the Head

Computed tomography (CT) imaging is increasingly used in emergency departments and trauma services and is being offered as a supplemental tool with autopsy in coroner's and medical examiner's offices throughout the United States. The availability of CT images in lieu of traditional X‐rays for medicolegal autopsies may lead to misinterpretation of images for forensic pathologists who are not familiar with these types of images. Forensic pathologists must become familiar with CT imaging, the basis of CT image formation and how to interpret CT images appropriately. We highlight potential pitfalls of CT image interpretation through two cases of fatal gunshot wounds of the head. Antemortem CT imaging available at the time of autopsy led to discrepancy between the initial image findings and the autopsy due to inexperienced manipulation of the images. With appropriate understanding of CT image interpretation and manipulation, forensic personnel should be able to avoid most sources of misinterpretation.