A simulation for exploring the effects of the "trait list" method's subjectivity on consistency and accuracy of ancestry estimations

The nonmetric "trait list" methodology is widely used for estimating ancestry of skeletal remains. However, the effects of the method's embedded subjectivity on subsequent accuracy and consistency are largely unknown. We develop a mathematical simulation to test whether variation in the application of the "trait list" method alters the ancestry estimation for a given case. Our simulation explores how variations in (i) trait selection, (ii) number of traits employed, and (iii) ancestry choice thresholds affect the ancestry estimation of an unidentified skeleton. Using two temporally and geographically diverse samples, the simulation demonstrates that trait selection, trait quantity, threshold choices, and the exclusion of high-frequency traits had minimal effect on estimation of general ancestry. For all data sets and Runs, Accuracy(AS) was maintained above 90%. The authors close with a discussion on the logistical issues present when choosing traits, and how to avoid ancestry bias.     

Injuries of the female genitalia in cases of sexual assault

Sexual violence is a global problem that particularly affects women and children. A retrospective analysis of 390 clinical-forensic examinations and 120 autopsies regarding injuries of the female genitalia in cases of sexual violence was performed. In the majority of cases no injuries of the female genitalia were found. Autopsy cases showed significantly more (and more serious) injuries of the genitalia than clinical forensic examinations (43 % vs. 25 %; p = 0.0004). Predominantly found were injuries of the external anogenital area, mostly tears or soft tissue lesions. In the current literature, data regarding the rate of injuries in victims of sexual violence vary strongly and their comparability is limited. Regarding the reconstruction of an offence, a forensic examination with an appropriate documentation of the injuries is evidently crucial.     

Variability of cannabinoid findings in blood

Cannabis products have been administered for many centuries; today, cannabis is the most widely used illegal drug all over the world. Nevertheless, the interpretation of cannabis findings in blood with regard to consumption behaviour and/or estimating the elapsed time since the last cannabis use is still a very challenging task. A wide variation of pharmacokinetic parameters has been observed even in experimental studies. Different chemical structures of precursors, smoking dynamics, pyrolysis of phytocannabinoids and frequency of drug use affect the amount of THC absorbed. Polymorphic enzymes are involved in phase-I-metabolism of THC. Pharmacological effects of other cannabinoids or medication on the pharmacokinetics of THC have not yet been studied in detail. Hydrolysis of cannabis conjugates may occur during storage of blood samples and processing of specimens for analysis; knowledge on the stability of cannabinoids in forensic specimens is still poor. Whether determination of cannabinoid conjugates may be useful is a matter of further consideration. At present, the broad variation of pharmacokinetic parameters and the limiting factors discussed in the present paper should be taken into account when using data from experimental studies for interpretation of analytical results in forensic case work.     

Death related to aortic coarctation in a young female during sexual intercourse

Coarctation of the aorta (CA) is diagnosed mainly in pediatric patients, and therapy is conservative if asymptomatic, but surgical treatment is required if advanced arterial hypertension is present. Moderate to severe forms contraindicate any type of physical activity requiring cardiac effort. Here, we describe the first documented death of an apparently healthy 35-year-old woman because of cardiac tamponade by rupture of an aortic aneurysm, possibly related to congenital CA, prolonged use of oxymetazoline hydrochloride, and physical and/or emotional stress during sexual activity. Our patient was asymptomatic for classical CA symptoms. The patient's breathing difficulties likely in hindsight were due not so much to nasal congestion, but rather to an ineffective oxygenation of the blood from the abnormal heart. In an attempt to treat the "nasal disease," the patient ingested chronic and excessive doses of decongestants, aggravating her fatal disease. The danger of inhaling large doses of nasal decongestants without an appropriate medical indication is highlighted here.     

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.     

Human dental age estimation by calculation of pulp-tooth volume ratios yielded on clinically acquired cone beam computed tomography images of monoradicular teeth

Abstract: Secondary dentine is responsible for a decrease in the volume of the dental pulp cavity with aging. The aim of this study is to evaluate a human dental age estimation method based on the ratio between the volume of the pulp and the volume of its corresponding tooth, calculated on clinically taken cone beam computed tomography (CBCT) images from monoradicular teeth. On the 3D images of 111 clinically obtained CBCT images (Scanora^®3D dental cone beam unit) of 57 female and 54 male patients ranging in age between 10 and 65 years, the pulp–tooth volume ratio of 64 incisors, 32 canines, and 15 premolars was calculated with Simplant^® Pro software. A linear regression model was fit with age as dependent variable and ratio as predictor, allowing for interactions of specific gender or tooth type. The obtained pulp–tooth volume ratios were the strongest related to age on incisors.     

Three-dimensional modeling of the various volumes of canines to determine age and sex: a preliminary study

Canines are usually used in anthropological and forensic sciences for sex and age determination. The best methods to estimate age are based on secondary dentine apposition, evaluated from periapical X-rays. The aim of this study was to propose a new method of sex and age estimation using 3D models to obtain more precise predictions using tooth volumes. Fifty-eight dental CT scans of patients aged 14-74 with a well-balanced sex ratio composed the sample. One hundred and thirty-three healthy canines were modeled (Mimics 12.0). The sample was divided into a training sample and a validation sample. An age formula was determined using the "pulp volume/tooth volume" ratio. Sex prediction was adjusted with total volumes. Applying the equations to the validation sample, no significant difference was found between the real and predicted ages, and 100% of the sex predictions were correct. This preliminary study gives interesting results, and this method is worth being tested on a larger data sample.     

So-called Spontaneous Human Combustion

A well-documented case of so-called Spontaneous Human Combustion is reported. Review of the literature shows that these strange observations have been reported since the 17th century, even in famous novels. There are several main features that may lead to help the diagnosis: the vicinity of the body is intact or nearly intact, some parts of the body are turned into ashes (usually the middle third of the body), whereas other parts are intact or nearly intact, burning of the body usually occurs postmortem, the cause of death is usually natural, there is often (but not always) high concentrations of blood alcohol, there is a source of heat near the body. It is indispensable to rule out a homicide by the examination of the body in situ, the autopsy, the toxicological and histopathological samples, the arson assessment, and a thorough police inquiry.     

Role of preoperative 3-dimensional computed tomography reconstruction in depressed skull fractures treated with craniectomy: a case report of forensic interest

Patients affected by cranial trauma with depressed skull fractures and increased intracranial pressure generally undergo neurosurgical intervention. Because craniotomy and craniectomy remove skull fragments and generate new fracture lines, they complicate forensic examination and sometimes prevent a clear identification of skull fracture etiology. A 3-dimensional reconstruction based on preoperative computed tomography (CT) scans, giving a picture of the injuries before surgical intervention, can help the forensic examiner in identifying skull fracture origin and the means of production.We report the case of a 41-year-old-man presenting at the emergency department with a depressed skull fracture at the vertex and bilateral subdural hemorrhage. The patient underwent 2 neurosurgical interventions (craniotomy and craniectomy) but died after 40 days of hospitalization in an intensive care unit. At autopsy, the absence of various bone fragments did not allow us to establish if the skull had been stricken by a blunt object or had hit the ground with high kinetic energy. To analyze bone injuries before craniectomy, a 3-dimensional CT reconstruction based on preoperative scans was performed. A comparative analysis between autoptic and radiological data allowed us to differentiate surgical from traumatic injuries. Moreover, based on the shape and size of the depressed skull fracture (measured from the CT reformations), we inferred that the man had been stricken by a cylindric blunt object with a diameter of about 3 cm.     

Neonatal freshwater drowning after birth in the bathroom

The macroscopic and microscopic findings in neonatal freshwater drowning are demonstrated on the basis of 3 exemplary cases of birth in the bathroom after concealed pregnancy. If the newborn is expelled under water and remains there until death, the lungs cannot be ventilated with air. In case of incomplete or only temporary submersion, aeration of the lungs may develop in the immediate postpartum period. The morphologic criteria of separate existence are critically discussed with respect to the presented findings.