Unusual suicide with a chainsaw

Described here is a case of suicide with the use of a chainsaw. A female suffering from schizophrenia committed suicide by an ingenious use of a chainsaw that resulted in the transection of her cervical spine and spinal cord. The findings of the resulting investigation are described and the mechanism of suicides with the use of a chainsaw is reviewed. A dry bone study was realized to determine the bone sections, the correlation between anatomic lesions and characteristics of chainsaw. The damage of organs and soft tissues is compared according to the kinds of chainsaw used.     

Application of the Iscan method to two- and three-dimensional imaging of the sternal end of the right fourth rib

Age determination is a major field of interest in physical and forensic anthropology. Among the different methods based on macroscopic skeletal study, the Iscan method, which analyzes the sternal end of the right fourth rib, is one of the most reliable. We applied the Iscan method to two- and three-dimensional multislice computed tomography (MSCT) reconstructions of the sternal end of the right fourth rib on 39 ribs. The intra-observer variability on MSCT reconstructions was good (gamma coefficient equal to 0.86; value of the Krippendorff's alpha reliability equal to 0.79); inter-observer variability on MSCT reconstructions was also good (gamma coefficient ranging from 0.82 to 0.88; value of the Krippendorff's alpha reliability ranging from 0.78 to 0.86). We demonstrated excellent agreement between the results of analysis of bone samples and those of the two- and three-dimensional images, in particular regarding bone projections, morphology of the pit and of its rim. The accuracy of age estimation did not significantly differ between the Iscan method applied to dry bones and the same method applied to MSCT images. Determination of the Krippendorff's alpha reliability coefficient for the inter-error method confirmed the agreement between phase estimations obtained with the two methods (ranging from 0.55 to 0.71). The real civil age was comprised in 21 cases out of 36 for assessment performed on dry bones and in 23 cases out of 36 on MSCT reconstructions, which represented 58.3% and 63.9%, respectively. Use of MSCT reconstructions in forensic anthropology offers many advantages: no bone preparation, no damage to bone material, and the possibility of application to living individuals.     

Identification of acepromazine in hair: an illustration of the difficulties encountered in investigating drug-facilitated crimes

After a drug-facilitated sexual assault (DFSA), a woman was found in a drowsy state at home. She remembered having drunk an unknown beverage by the accused. Blood samples (collected 8 hours after the DFSA), two glasses, and a teaspoon seized by the police were analyzed. Acepromazine, a phenothiazine tranquilizer used in human and veterinary medicine, was detected in the residue of one of the glasses. In spite of acepromazine absence in the victim's blood, the possible use of acepromazine in the DFSA was reported to the police. Two weeks later, a suspect admitted having orally administered acepromazine to the victim. Using a liquid chromatography-tandem mass spectrometry method, this compound was subsequently detected (31 pg/mg) in a sample of the victim's hair collected a month and a half after the DFSA. A potential short elimination half-life in humans and/or the well-known in vitro degradation of acepromazine could explain the negative blood result. DFSA toxicological investigations are challenging and can be complicated when a rather unusual substance is concerned. In particular, special care should be taken when interpreting the results, taking into account elimination and/or instability data, when available.     

A calculation of the theoretical significance of matched bullets

Abstract:  The comparison and identification of bullets from the striations that appear on their surfaces, after they have been fired from a gun, have been practiced since the 1920s. Although the significance of the correspondences of these impression marks has been empirically justified, there is a conspicuous absence of any theoretical foundation for the likelihood. What is presented here is the derivation of the formulae for calculating the probability for the correspondence of the impression marks on a subject bullet to a random distribution of a similar number of impression marks on a suspect bullet of the same type. The approach to the calculation entails subdividing the impression marks into a series of individual lines having widths equal to the separation distance at which a misalignment of striations between the two bullets cannot be distinguished. This distance depends upon the resolution limit imposed by the microscope as well as by the visual acuity of the examiner. A calculation of the probabilities for finding pairs and triplets of consecutively matching lines on nonmatching bullets, by an examiner with normal perception using a microscope at 40× magnification, produces values that agree well with the empirical probabilities determined by Biasotti in the 1950s and when determined for larger consecutive sequences suggest that they are extremely unlikely to occur. The formulae can be used to determine the probabilities for the random occurrence of any sequence of striae and provide a straightforward way to quantitatively justify the significance of a specific match between any two bullets.     

Child abuse: practical application of autopsy, radiological, and microscopic studies

A 17-month-old male infant died at home. The infant's right arm was immobilized because of a humeral fracture 1 month earlier. The circumstances of death appeared unclear to the police investigators and a medicolegal autopsy was carried out. External examination revealed diffuse ecchymoses of varying color. Postmortem imaging was performed prior to autopsy (X-rays, multislice computed tomography [MSCT], and focused brain magnetic resonance imaging [MRI]). These investigations revealed four rib fractures of varying ages, one of which was posterior. Cerebral and pericerebral traumatic lesions were also diagnosed: bilateral subdural hematomas, intraventricular, meningeal, and interpedoncular hemorrhages. In the abdomen, fresh blood was visible within the anterior abdominal wall and the mesenteric root. Autopsy and microscopic study confirmed these lesions. This case report illustrates the valuable assistance rendered by MSCT and MRI to diagnose abuse when a child has died in unclear circumstances.     

大鼠急性心肌缺血后肌浆网RyR2 mRNA表达变化

目的 研究大鼠急性心肌缺血后心肌肌浆网兰尼碱受体蛋白2(ryanodine receptor 2,RyR2)mRNA表达的变化.方法 将SD大鼠分为正常对照组、心肌缺血组和缺血性猝死组.采用腹腔注射垂体后叶素的方法复制大鼠急性心肌缺血和猝死模型,对心肌进行半定量荧光RT-PCR检测,观察RyR2 mRNA表达水平的变化.结果 与正常对照组相比,不同时间和不同程度的急性心肌缺血后心肌肌浆网RyR2 mRNA表达均显著降低(P<0.05).结论 心肌缺血性损伤可诱导心肌钙调控蛋白RyR2 mRNA表达下调.     

Perforating gunshot to the head with a power-actuated tool

The article describes a shortly survived suicide with a powder-actuated tool. A 51-year-old man shot all through his head from the right to the left temple. The pin produced an extensive area of destruction in the brain tissue, but neither in the hospital nor during the autopsy was any projectile found. Finally the pin was detected in a metal fitting of the bed in which the man had killed himself. The suicide instrument was a powder-actuated tool firing a metal pin after igniting a cartridge. Unlike a nail gun using compressed air, pins fired by means of a propellant reach a velocity of up to 150 m/s thus developing a higher destructive potential.