Child and adolescent victims in forensic autopsy: a 5-year retrospective study

Children of more than 3 years of age and adolescents have been largely overlooked in the forensic literature, especially the 4-9 age group. Thus, the present study was undertaken to address this particular issue of child and adolescent victims in forensic autopsies. On a 5-year period (2000-2004) in Quebec province (Canada), all forensic autopsy cases of children and adolescents from 4 to 19 years of age were retrospectively studied. A total of 223 cases of child and adolescent deaths (148 males, 75 females; 6.6% of all forensic autopsies) were reviewed. Age, gender, manner of death and cause of death were analyzed for all victims organized into three groups of age: 4-9, 10-14, and 15-19. Moreover, homicide cases (n = 54) are further analyzed in terms of method(s) used (firearm, sharp force, asphyxia, blunt force, intoxication). This 5-year retrospective study may contribute to a better understanding of typical deaths in the 4-19 group of age and therefore, bring a working basis for the forensic pathologist or medical examiner/coroner.     

原子力显微镜在法庭科学中的应用及展望

原子力显微镜是一种具有纳米级分辨率,可观察物体表面形貌和表面结构的新型显微镜。本文对原子力显微镜的工作原理、工作模式、优点,以及原子力显微镜在法庭科学中应用进行了综述。     

Poisoning deaths in Central China (Hubei): A 10-year retrospective study of forensic autopsy cases

A retrospective study of autopsy cases was conducted at the Department of Forensic Medicine, Tongji Medical College (DFM-TMC), in Hubei, China to describe the characteristics of poisoning deaths from 1999 to 2008. A total of 212 poisoning deaths were investigated by DFM-TMC during the 10-year period. The poisoning deaths ranged from 17 cases in 1999 to 27 cases in 2008. Of the 212 cases, 82 deaths (38.7%) were from pesticides, 36 deaths (17.0%) from carbon monoxide, 34 deaths (16.0%) from drugs, 22 deaths (10.4%) from alcohol, 17 deaths (8.0%) from other chemicals, 15 deaths (7.1%) from poisonous plants and animals, and six deaths (2.8%) from heavy metals. Of the 82 pesticide poisoning deaths, 43 (52.4%) cases were caused by rodenticides, mainly tetramine (N = 39). The majority of poisoning deaths were accidents (63.7%), followed by suicides (25.9%) and homicides (3.8%). The manner of death could not be determined in 14 cases (6.6%).     

Determination of an effective housekeeping gene for the quantification of mRNA for forensic applications

The potential application of mRNA for the identification of biological fluids using molecular techniques has been a recent development in forensic serology. Constitutively expressed housekeeping genes can assess the amount of mRNA recovered from a sample, establish its suitability for downstream applications, and provide a reference point to corroborate the identity of the fluid. qPCR was utilized to compare the expression levels of housekeeping genes from forensic-like body fluid stains to establish the most appropriate assessment of human mRNA quantity prior to profiling. Although variability was observed between fluids and individuals, results indicated that beta-2 microglobulin exhibited the highest expression for all body fluids examined and across donors. A one-way analysis of variance was performed for housekeeping gene variability between donors (at the α, 0.05, significance level), and the results indicated significant differences for semen, vaginal secretions, and menstrual blood.     

Antemortem dental records: attitudes and practices of forensic dentists

This study was designed to provide insight concerning the attitudes and practices of forensic dentists regarding antemortem dental records reviewed for purposes of dental identification. Forensic dentists were invited to participate in a 10 item survey. The majority of the respondents reported a considerable amount of experience in dental identifications of the deceased. Sixty-six percent reported having suspected dental negligence or fraud in their antemortem record reviews. Only 17% believe that a forensic dentist should report suspected dental negligence, while 31% agree that dental fraud should be reported. Their response to additional issues addressed in the study suggests diversity in the practices and attitudes of forensic dentists in the use of antemortem dental records. In conclusion, opening a dialogue among practicing forensic dentists may lead to a standardized set of recommendations by the appropriate societies in the forensic dental community.     

镫骨肌声反射推算听敏度及法医学评价

听力损害的法医学鉴定，须采用客观、准确、定量的听力测验方法。声镫骨肌反射具有客观、设备简单、操作方便快捷、检查费用低廉等优点。国外学者对此进行了较多研究，结果差异较大。国内这方面研究较少。本文按严格纳入标准，选择大样本运用逐步多元回归统计分析，建立了推算ＰＴＡ的数学模型，经统计学显著性检验，新建方程具有较高准确性。且可信度均较过去推算方法为好。年龄、中耳阻抗轻度异常对推算准确性无显著影响。声镫骨肌推算听敏度数学模型仍可作为法医学鉴定中客观评定听力下降程度的首选常规方法。     

国产NuHi-POP4与ABI POP-4在毛细管电泳分离效果的比较

目的比较国产基因分离胶NuHi-POP4与美国产商品ABI POP-4在法医鉴定应用中的分离性能。方法以国产基因分离胶NuHi-POP4和美国产的ABI POP-4为研究对象,分别考察其在毛细管电泳过程中对标准品LIZ500和实际样品的分离效果,并统计其电泳参数,包括电泳时间、电流、单碱基分辨率以及线性关系等,从而来比较两种胶的分离性能,评价其性能。结果 NuHi-POP4与ABI POP-4相比,不仅可以显著缩短内标和样品的分析时间,同时还表现出电流稳定、分辨率高、线性关系好等特点。结论国产NuHi-POP4与美国ABI POP-4相比,同样具有稳定、快速、高分辨等优势,结果准确可靠。     

Forensic applications of sodium rhodizonate and hydrochloric acid: a new histological technique for detection of gunshot residues

Demonstration of the presence of lead residues deriving from gunshot in skin and underlying tissues is essential for the correct forensic analysis of numerous legal cases. Optical microscopy remains the fastest, cheapest diagnostic technique, even though its sensitivity and specificity are poor because of the scarce quantity of histological tissue that can be examined and possible environmental lead pollution. To confirm the presence of lead from gunshot residues, we applied to histological sections of human skin a technique proposed by Owens and George in 1991 for macroscopic detection of lead on the clothing of shooting victims, involving a reaction with sodium rhodizonate and subsequent confirmation by color change on application of HCl. Our results demonstrate the technical possibility of using this macroscopic technique even on histological samples and support the need for further studies on a larger series of cases correlated with the type of ammunition and firing distance.     

Naturalistic decision making in forensic science: toward a better understanding of decision making by forensic team leaders

This study uses the naturalistic decision-making (NDM) perspective to examine how Dutch forensic team leaders (i.e., the officers in charge of criminal forensic research from the crime scene until the use of laboratory assistance) make decisions in real-life settings and identifies the contextual factors that might influence those decisions. First, a focus group interview was conducted to identify four NDM mechanisms in day-to-day forensic decision making. Second, a serious game was conducted to examine the influence of three of these contextual mechanisms. The results uncovered that forensic team leaders (i) were attracted to obtain further information when more information was initially made available, (ii) were likely to devote more attention to emotionally charged cases, and (iii) used not only forensic evidence in the decision making but also tactical, unverified information of the police inquiry. Interestingly, the measured contextual influences did not deviate significantly from a control group of laypeople.     

Spread and habitat selection of Chrysomya albiceps (Wiedemann) (Diptera Calliphoridae) in Northern Italy: forensic implications

Abstract: Habitat selection exploited by Chrysomya albiceps during its initial spread in Northern Italy was analyzed in relation to landscape structure. The results of two short studies and a case report are here discussed. C. albiceps was not found on experimental pig carcasses in the urban area of Pavia. It was missing in the woody mountains surrounding Lecco, but it was found in the same area, at a lower altitude, within the typical “urban sprawl” landscape. It was then recorded in a natural reserve, among a rich carrion‐fly population. Indications coming from habitat selection suggest that C. albiceps has not yet saturated its potential ecological niche in newly colonized areas of Northern Italy. Factors like temperature, altitude, and interspecific competition can act as limiting factors, affecting habitat selection and distribution in newly colonized areas; the influence of those factors has to be taken into account for forensic purposes.     

Concentrations of Opiates and Psychotropic Agents in Polydrug Overdoses: A Surprising Correlation Between Morphine and Antidepressants

Abstract: The relationship between postmortem concentrations of morphine and co‐detected psychoactive drugs in fatal overdoses is examined. Morphine and other drugs were detected in 161 medicolegal autopsy cases. Subsets of these morphine‐positive cases based on drug class were established, including opioids, antidepressants, ethanol, benzodiazepines, and “other.” Each subset was split into high or low concentration groups based on median drug concentrations. Morphine concentrations of the [high] and [low] groups were compared, with no significant difference in morphine concentration identified in the opioid, ethanol, or benzodiazepine subsets. The “other” drug class was too heterogeneous for statistical assessment. Morphine concentrations did show a significant direct relationship (p = 0.01) with antidepressants, namely increased concentrations of antidepressant drugs are associated with an increased concentration of morphine. This trend probably remains even after excluding cocaine‐positive cases. The unsuspected finding that postmortem concentrations of antidepressants positively correlate with morphine levels may be important in the treatment of depression in drug addicts.     

Cerebral hypoxia and ischemia: the forensic point of view: a review

In cases with suspected brain anoxia/ischemia and hypoxia/hypoxemia a neuropathological investigation should give additional information to elucidate the cause of death and its pathophysiological mechanisms. Primary ischemic brain damage is associated with morphological and biochemical alterations. While acute ischemic neuronal injury reveals axon sparing and selective neuronal lesions due to the release of large quantities of glutamate, late neuronal death is associated with antiapoptotic growth factors, and decreased expression of microtubule-associated proteins and tubulin. On the morphological level ischemia can be detected by necrosis of neurons, proliferation of microglia, and astrocytes in vulnerable regions of the brain. In cases of permanent ischemia the so-called pale nervous cell injury is observed, in cases of partial perfusion the so-called dark nerve cell injury and apoptosis are detectable. In spite of the considerable advantages of recent research, presently there is no reliable qualitative marker to ascertain death due to acute hypoxic or ischemic events.     

Different Mechanisms of Decapitation: Three Classic and One Unique Case History

Abstract: Three classic cases and one exceptional case are reported. The unique case of decapitation took place in a traffic accident, while the others were seen after homicide, vehicle‐assisted suicide, and after long‐jump hanging. Thorough scene examinations were performed, and photographs from the scene were available in all cases. Through the autopsy of each case, the mechanism for the decapitation in each case was revealed. The severance lines were through the neck and the cervical vertebral column, except for in the motor vehicle accident case, where the base of skull was fractured. This case was also unusual as the mechanism was blunt force. In the homicide case, the mechanism was the use of a knife combined with a saw, while in the two last cases, a ligature made the cut through the neck. The different mechanisms in these decapitations are suggested.     

Asphyxiation by Occlusion of Nose and Mouth by Duct Tape: Two Unusual Suicides

Abstract:  The most recent U.S. statistics (2005) determined that 22.2% of suicides are by suffocation. This number likely includes suicidal hanging. Based on previous reports the majority of nonhanging suicidal asphyxiations are accomplished by securing a plastic bag over the head. We report two instances of a far less common method of suicidal asphyxiation, occlusion of the nose and mouth by duct tape. One was a 47-year-old man with a history of paranoid schizophrenia with suicidal ideation and the other was a 52-year-old man who was depressed due to gambling debts. The value of scene investigation, including review of available video surveillance to determine the manner of death is highlighted.     

Development and validation of a simple GC-MS method for the simultaneous determination of 11 anticholinesterase pesticides in blood--clinical and forensic toxicology applications

Anticholinesterase pesticides are widely used, and as a result they are involved in numerous acute and even fatal poisonings. The aim of this study was the development, optimization, and validation of a simple, rapid, specific, and sensitive gas chromatography-mass spectrometry method for the determination of 11 anticholinesterase pesticides (aldicarb, azinphos methyl, carbofuran, chlorpyrifos, dialifos, diazinon, malathion, methamidophos, methidathion, methomyl, and terbufos) in blood. Only 500 μL of blood was used, and the recoveries after liquid-liquid extraction (toluene/chloroform, 4:1, v/v) were more than 65.6%. The calibration curves were linear (R(2) ≥ 0.996). Limit of detections and limit of quantifications were found to be between 1.00-10.0 and 3.00-30.0 μg/L, respectively. Accuracy expressed as the %E(r) was found to be between -11.0 and 7.8%. Precision expressed as the percent relative standard deviation was found to be <9.4%. The developed method can be applied for the investigation of both forensic and clinical cases of accidental or suicidal poisoning with these pesticides.     

A Minimally Invasive Technique for the Detection and Analysis of Pulmonary Fat Embolism: A Feasibility Study*

We investigated the feasibility of postmortem percutaneous needle biopsy (PNB) for obtaining pulmonary samples adequate for the study of pulmonary fat embolism (PFE). Samples of both lungs were obtained from 26 cadavers via two different methods: (i) PNB and (ii) the double-edged knife technique, the gold standard at our institute. After water storage and Sudan III staining, six forensic pathologists independently examined all samples for the presence and severity of PFE. The results were compared and analyzed in each case regarding the vitality of the PFE and its relationship to the cause of death. The results showed that PFE was almost identically diagnosed and graded on the samples obtained via both methods. The discrepancies between the two techniques did not affect the diagnoses of vitality or cause of death related to PFE. This study demonstrates the feasibility of the PNB sampling method for the diagnosis and interpretation of PFE in the postmortem setting.     

Virtual autopsy and forensic anthropology of a mummified fetus: a report of one case

A jar containing the mummified body of a fetus was found in a bush near a building. Full-body multislice computed tomography (MSCT) was performed prior to autopsy to study the bones and internal organs. Age was estimated by measuring femoral and tibial lengths and examining the temporal and occipital bones. The results were then compared with the autopsy and histopathological findings. MSCT was superior to autopsy for examination of the bones and internal organs. Autopsy was difficult because of the fragility of the dried corpse. MSCT determined the gestational age of the fetus and excluded skeletal abnormalities. Estimated age was similar with the two methods used. However, the major advantage of MSCT was rapid measurement of bones or anatomical regions which are difficult to examine during autopsy and which required specific preparation for further anthropological study. This case report illustrates the possibilities offered by MSCT for studying mummified bodies, even fetuses.     

Haplotypic blocks of X-linked STRs for forensic cases: study of recombination and mutation rates

In complex kinship cases, markers situated in haplotypic blocks may provide additional clues to other unlinked markers. We have established a protocol to amplify six X-chromosome microsatellites, located in two haplotype blocks, using PCR with fluorochrome-labeled primers and capillary electrophoresis. The segregation stability was explored in 92 unrelated families with individuals from three generations. Sixty-one different haplotypes were found in the DXS10079-DXS10074-DXS10075 block in the grandfathers and 96 in the mothers, with estimated haplotype diversities of 0.9828 and 0.9842, respectively. Fifty and 73 different haplotypes were found in the DXS6801-DXS6809-DXS6789 block in the grandfathers and the mothers, with estimated haplotype diversities of 0.9711 and 0.9742, respectively. We observed 10 between-cluster and one within-cluster recombinations in 99 female meioses. The overall per-locus mutation rate was 0.0034. This protocol allows for the characterization of the alleles of two sets of linked markers of the X-chromosome that can be useful in complex forensic cases.     

Motor vehicle collisions and their demographics: a 5-year retrospective study of the Hamilton-Wentworth Niagara region

This retrospective study examined population demographics associated with motor vehicle collision (MVC) fatalities over a 5-year period in the Hamilton-Wentworth Niagara region. Variables were drawn from the five factors proposed by Fierro (1) for investigating deaths caused by transportation: human, chemical, environmental, vehicular, and highway. Factors analyzed included age, gender, position to the vehicle, site(s) of injury, toxicology, environmental contributors, and vehicular findings. From 1999 to 2004, there were 321 MVC fatalities that primarily involved males 20 to 29 years of age and commonly drivers or pedestrians. Cars and trucks were the most frequent vehicles. Fatalities occurred most often on local and regional roads on Fridays and Sundays between 6 pm and 6 am. Mechanical failure and weather conditions were not significant contributors. Toxicological analyses (275/321) were performed on the majority of the study population. Ethanol was present in isolation and with other substances, especially cannabis, mostly in male drivers 20-59 years of age.