Fatal Wounds Sustained from “Falling Bullets”: Maintaining a High Index of Suspicion in a Forensic Setting

Celebratory gunfire injuries from “falling bullets” occur when guns are fired into the air during celebrations without realizing that this can cause serious injuries or even fatalities. Fatal celebratory gunfire injury is an uncommonly reported event in the continental United States. Our electronic database was queried for homicides occurring within days of July 4th and December 31st over a 14‐year period. We describe two cases of fatal gunfire injury due to celebratory gunfire occurring during New Year's Eve in Southern Florida. The relevant literature is reviewed. These case reports illustrate that fatal gunfire injuries sustained from “falling bullets” may pose as an unexpected mimic to sudden natural deaths especially in patients with prior medical history. A high index of suspicion to recognize such injury is required particularly during holidays.     

Microscopic Analysis of Sharp Force Trauma in Bone and Cartilage: A Validation Study,,

Sharp force trauma research lacks agreement on reported error rates for correctly identifying toolmark characteristics on bone and cartilage. This study provides error rates for determining blade class (serrated, partially serrated, nonserrated) and type of edge bevel (left, right, even). Three analysts examined cuts to a wax medium, cartilage, and bone using two types of microscopes. Additionally, the observers examined impressions taken from the wax medium and the cartilage. Overall, a total of 504 observations were performed. Serrated blades were distinguishable from nonserrated blades due to their patterned striations. Some difficulties were encountered in distinguishing serrated and partially serrated blades; however, when these groups were considered together as one classification type (serrated), classification accuracy improved from 79% to 96%. Classification accuracy for edge bevel was 65%. Error rates were similar when comparing direct observation of the cut marks versus indirect observation (impressions). Additionally, the type of microscope used did not affect error rates.     

大鼠骨骼肌挫伤后ASCT2 mRNA的表达变化

目的应用实时定量PCR技术检测大鼠骨骼肌挫伤后细胞中性氨基酸载体ASCT2 mRNA表达,分析其与挫伤时间的关系。方法建立大鼠骨骼肌挫伤模型,分别取伤后4、8、12、16、20、24、28、32 h及对照组检材。提取总RNA,逆转录合成第一链的cDNA,以RPL13为内参基因进行荧光定量检测,采用2-△△Ct法比较其与对照组肌肉组织中ASCT2 mRNA的相对表达量。结果损伤组肌肉组织中ASCT2 mRNA在挫伤后12、16h表达量分别为对照组的196.40%和189.15%,损伤后4、8、20、24、28、32h ASCT2 mRNA表达量与对照组相比无统计学差异(P>0.05),说明ASCT2 mRNA在损伤12～16h其表达量较正常组及其他损伤时间组要高,而在损伤20h以后ASCT2 mRNA表达量又降至正常水平。结论大鼠骨骼肌挫伤后32h之内ASCT2 mRNA的表达有一定的时间规律性,可望作为推断骨骼肌损伤时间的指标之一。     

Case Report of a Migrating Bullet: An Unusual Cause of Postmortem Confusion

Migrating bullets are rare sequelae of penetrating gunshot wounds. Such cases have been described in the neurosurgical literature because they can produce complications in the management of patients such as decline in neurologic status, delays in rehabilitation, and difficulties in bullet removal. In contrast, few postmortem reports have described this phenomenon. We report a case of a gunshot wound in which the projectile entered the left side of the head and traversed to the right frontal area as documented by CT scan on hospital admission. At autopsy, the bullet was noted to have migrated back to the left side of the head from where it was recovered. Medical examiners need to be aware of this unusual phenomenon of retained intracranial projectiles.     

Characteristics of Bone Injuries Resulting from Knife Wounds Incised with Different Forces

The aim of this research was to experimentally determine the characteristics of incised bone wounds, which are commonly found in defense injuries. A specially constructed pivoting arm device was used to inflict wounds with controlled forces and direction. Five knives were selected to inflict the wounds on porcine forelimbs. Eight incised wounds were made per knife per force. A larger knife and a greater force caused longer and wider bone wounds. Comparisons of individual knives at the two forces produced varying results in the bone wounds. A correlation was seen between the force and the length (r = 0.69), width (r = 0.63), and depth (r = 0.57) of bone wounds. Serrated‐edge and nonserrated knives can be distinguished from the appearance of the wound. The outcomes may be applicable in forensic investigations to ascertain the forces associated with incised wounds and identify the specific knife used.     

枪弹创前置物射入口形态学的实验研究

为建立前置物射入口与典型射入口的检验鉴别方法，使用国产54式7.62mm口径手枪及56式7．62mm口径半自动步枪，以3m的距离射击约克夏种白猪义3只，同时以各种玻璃、木板。汽车门、动物躯干等物质作为中间障碍物，制成前置物射入口36例，并与对照组6例射入口进行对比观察。结果显示，前置物射入口较典型射入口增大，撕裂，创线挫伤增宽，创周出现卫星创或假点彩，创道内异物及弹头严重变形。此检验诊断方法有助于法医在实际检验中对射击距离的判断和对现场环境的分析。     

小鼠皮肤切创后calpain1和calpain2的表达

目的观察小鼠皮肤切创愈合过程中calpain1和calpain2表达变化。方法应用免疫组织化学染色技术检测小鼠皮肤切创后calpain1和calpain2的表达。结果对照组的calpain1和calpain2均有表达,伤后1d calpain1阳性细胞率显著增加,达最大值。伤后3d阳性细胞比率显著下降。伤后5d阳性细胞比率再次显著增加,以后逐渐下降。伤后1d calpain2阳性细胞比率显著增加,伤后3d阳性细胞比率显著下降,达最低值。伤后5d阳性细胞比率再次显著增加,达最大值。伤后7d至10d,阳性细胞比率逐渐下降。结论小鼠皮肤切创后,calpain1和calpain2的表达随愈合时间而呈现双峰式变化。     

Shooting Through Clothing in Firearm Suicides

Abstract: There is a longstanding empirical rule that people who commit suicide rarely shoot through their clothing, but rather put it aside to expose the nude skin. Signs of shots through clothing have always been considered suspicious, raising presumptions of the presence of an abettor. Our report, based on a retrospective study of fatal suicidal firearm injuries from the years 1980 to 2007, points out that suicide victims only rarely remove clothing from the site of the future entry wound. The report covered 43 cases with fatal gunshot wounds in the area of the thorax, with only four persons (9%) removing the clothing present in the area of the subsequent self‐inflicted wound. Defects present on the clothing of a victim cannot, therefore, be understood as an absolute criterion for disproving the possibility of suicide, and nor do they necessarily indicate an unfortunate accident or homicide. If, however, the suicide victim removes the clothing from the area of the future wound, then this is almost always an indication of suicide.     

小鼠皮肤切创愈合过程中M_3型乙酰胆碱受体的表达

目的 探讨小鼠皮肤切创愈合过程中损伤区M3受体的表达及其随时间的变化规律.方法 应用免疫组织化学染色和Western印迹技术检测小鼠皮肤切创后不同时间段M3受体的变化情况.结果 正常皮肤组织的表皮、毛囊、皮脂腺、汗腺、皮肌层等均表达M3受体.伤后6～12h,损伤区M3受体阳性细胞以多形核粒细胞为主;1～3d,M3受体阳性细胞以单个核细胞和成纤维细胞为主;5～14d,M3受体阳性细胞主要为成纤维细胞.阳性细胞率在伤后6～12h逐渐增高,12h达高峰,1～5d略有下降,但保持较高水平,7d阳性细胞率再次达到峰值,随后逐渐降低.通过Westem印迹法检测显示,各个时间段均有M3受体阳性条带,其中12h和7d为M3受体两个表达高峰.结论 多形核粒细胞、单个核细胞和成纤维细胞均表达M3受体,提示其可能在皮肤切创愈合过程中起重要的作用;M3受体表达的规律性变化可用于损伤时间的推断.     

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.