Predicting the Postmortem Submersion Interval for Human Remains Recovered from U.K. Waterways*

Abstract: This article aims to increase accuracy in estimating the postmortem submersion interval (PMSI) for bodies recovered from rivers in the United Kingdom. Data were collected from closed case files, crime scene reports, and autopsy files concerning bodies recovered over a 15‐year period from the River Clyde, Scotland, and the River Mersey and canals in northwest England. One hundred and eighty‐seven cases met the study criteria and were scored by quantifying the overall amount of decomposition observed in each case. Statistical analysis showed that the duration of a body’s submergence in water and the temperatures to which it was exposed, as measured in accumulated degree days (ADD), had a significant effect on the decay process. Further analysis indicated that there were no significant differences in decomposition between the waterways. By combining the data from all study samples, it was possible to produce a single linear regression model for predicting ADD from observed decomposition.     

Death of a 10‐Month‐Old Boy After Exposure to Ethylmorphine

Abstract: Ethylmorphine, an opiate that is partially metabolized to morphine, is a common ingredient in antitussive preparations. We present a case where a 10‐month‐old boy was administered ethylmorphine in the evening and found dead in bed the following morning. Postmortem toxicological analyses of heart blood by gas chromatography‐mass spectrometry and liquid chromatography‐mass spectrometry revealed the presence of ethylmorphine and morphine at concentrations of 0.17 μM (0.054 mg/L) and 0.090 μM (0.026 mg/L), respectively. CYP2D6 genotyping showed that the deceased had an extensive metabolizer genotype, signifying a “normal” capacity for metabolizing ethylmorphine to morphine. The autopsy report concluded that death was caused by a combination of opiate‐induced sedation and weakening of respiratory drive, a respiratory infection, and a sleeping position that could have impeded breathing. This is the first case report where the death of an infant has been linked to ethylmorphine ingestion.     

Vitreous Humor: Biochemical Constituents in Estimation of Postmortem Interval*,†

Abstract: Analysis of biochemical constituents of the vitreous humor can be useful in determining the postmortem interval as there is proportionate postmortem rise of potassium and fall in sodium concentration. We studied 120 autopsy cases to determine the utility of potassium, sodium, calcium, and chloride levels, and sodium/potassium ratio in estimating the postmortem interval. There was a linear relationship between vitreous potassium concentration and postmortem interval, whereas an inverse relationship between vitreous sodium/potassium ratio and postmortem interval was noted. Other factors like age, sex, cause of death, season of death, and refrigeration of sample did not influence the vitreous humor potassium values. Using the statistical tools, a new formula was derived to determine the postmortem interval based on the potassium concentration and a review of previous literature is presented. Hence, the findings of this study supported a central role of vitreous humor biochemistry in many postmortem forensic and pathological evaluations.     

Preliminary Studies into the Characterization of Chemical Markers of Decomposition for Geoforensics*

Abstract: In this paper, we report the results of our preliminary studies into chemical characterization of the fluids produced during decomposition in the absence of a soil matrix. Pig (Sus domestica) carcasses were used to model the human decomposition process in two separate locations, Western Australia (Perth) and Canada (Oshawa). Analysis involved simple dilution and filtration of the decomposition fluids followed by gas chromatography–mass spectrometry. Several previously unreported compounds were detected in the decomposition fluid samples during the trials, including benzeneacetic acid, benzenepropionic acid, 2‐piperidone, and isocaproic acid. Possible biosynthetic pathways for some of the compounds produced are proposed. Further research trials are required, particularly in the presence of soil matrices.     

利用嗜尸性蝇类生活史推测死亡时间

目的积累一些嗜尸性蝇类生活史的资料及群落组成的季节性变动规律。方法采用动物尸体作诱饵,分别对自然飞到诱饵上繁殖生长的8种嗜尸性蝇类的生活史及群落组成的季节性变动规律进行观察研究。结果夏季高温时段蝇类群落组成物种较为丰富,冬季低温时段蝇类种群较为单一。常见8种嗜尸性蝇类虫态经历时间在气温高时较短,气温低时较长。结论嗜尸性蝇类生活史及群落组成的季节性变动规律可为推测死亡时间提供依据。     

小鼠肝组织GAPDH mRNA降解与死亡时间关系

目的探讨小鼠在不同的死亡方式下肝组织管家基因甘油醛-3-磷酸脱氢酶(glyceraldehyde-3-phosphate dehydrogenase,GAPDH)mRNA降解与死亡时间(postmortem interval,PMI)的关系。方法将60只NIH小鼠分别采用窒息法和断颈法处死,分别置于10℃和25℃温控系统内,利用两步法RT-PCR技术和核酸蛋白测定仪检测小鼠肝组织中GAPDH mRNA在死后0～48h的降解情况。结果在10℃温控系统内的小鼠死后0～48h及25℃温控系统内的小鼠死后0～36h肝组织均可检测到GAPDH mRNA,且其扩增产物呈规律性下降趋势。结论小鼠死亡后肝组织GAPDH mRNA降解与PMI呈负相关,可为PMI推断提供一种新的观测指标。     

兔死后角膜内皮细胞核DNA降解随死亡时间变化规律

目的研究兔死后角膜内皮细胞核DNA降解与死亡时间的关系。方法应用单细胞凝胶电泳(SCGE)技术结合荧光显微镜和专业的计算机图像分析技术,检测27只家兔死后48h内不同时间点角膜内皮细胞核DNA降解情况。结果家兔死后角膜内皮细胞产生彗星现象,彗星样细胞出现率于兔死后6h开始逐渐增加。死后6～18h彗星样细胞出现率增加缓慢,死后24～36h出现率上升较快;死后36～48h彗星样细胞出现率上升缓慢,但仍始终保持在较高的水平上(M185.4%),其回归方程为y=-0.0096x2+2.4548x+5.7964,与死亡时间呈正相关(R2=0.9743)。结论家兔死后角膜内皮细胞彗星样细胞出现率随死亡时间增加而逐渐增加。     

To Test or Not To Test?: The Value of Toxicology in a Delayed Overdose Death

A case demonstrating the necessity of thorough death investigation processes where toxicology plays an active role is presented. A 33‐year‐old white man presented to the emergency room in respiratory distress after an overdose episode where he was revived on the scene by fire rescue. His condition continued to deteriorate and he expired 6 days after the initial incident. No admission specimens were available for testing; however, there were specimens drawn 4 and 5 days after the incident. Drug paraphernalia from the scene was obtained by the laboratory through collaboration with local law enforcement. Drug paraphernalia was initially tested in the laboratory and after obtaining the results, the antemortem and postmortem specimens were tested identifying mitragynine and U‐47700, among other drugs. These results indicate the value in obtaining and testing drug paraphernalia, and the value of testing antemortem specimens even in the event of a delay.     

A Case of Fatal Dehydration During Police Custody

In the forensic literature, fatal dehydration predominantly concerns young children or incapacitated elderly persons. The postmortem diagnosis of fatal dehydration can be challenging to confirm, especially if the preceding circumstances are unknown. Here presented is a case of a 23‐year‐old man who died while held in an isolation cell during police custody for 18 days. Autopsy findings were unspecific, but vitreous fluid analysis showed 192 mmol/L sodium, 179 mmol/L chloride, 16 mmol/L potassium, 352 μmol/L (3.98 mg/dL) creatinine, and 81 mmol/L (226.9 mg/dL) urea nitrogen. Based on the findings and circumstances, the cause of death was determined as severe dehydration and manner of death accident. This case illustrates the importance of performing postmortem biochemistry.     

The Role of Postmortem Computed Tomography in the Evaluation of Strangulation Deaths

We explored the value of postmortem computed tomography (PMCT) to augment autopsy in evaluating strangulation fatalities. A literature search identified 16 studies describing autopsy findings in 576 deaths and two studies describing autopsy and PMCT findings in six deaths. Similar cases were identified from our institution, yielding 130 deaths with autopsy findings and 14 deaths with both autopsy and PMCT findings. The presence of laryngohyoid fracture and soft tissue hemorrhage was compared from autopsy and autopsy+PMCT cases. The detection rates of fractures in autopsy and autopsy+PMCT cases were not significantly different. PMCT identified all fractures observed at autopsy and five fractures not identified. While PMCT may not detect soft tissue injuries in decomposed remains or subtle internal hemorrhages in neck injury, it is equally able to detect bony injuries as autopsy and might surpass autopsy in detecting subtle fractures. We conclude PMCT is useful to supplement autopsy in strangulation cases.