International Journal of Legal Medicine最新文献

Estimation of the exposure temperature of skeletal remains can be done by means of colourimetry and a previously published decision model for the colourimetric data, resulting in clusters that represent a range of exposure temperature. The method was based on thermally altered freshly burned human skeletal remains. However, in practice the origin or pre-burning condition of (possibly fragmentary) burned remains can be unknown. Further, in order to use the colourimetric analysis, and accompanying decision model, it is important to have a reference or test set. Fresh human material is not available for this purpose in all countries. Hence, the classification accuracy of the decision model was tested for, in some countries more readily available substitutes for fresh bone; embalmed human bone and non-human bone. The model yielded high accuracies for these sample materials, making it possible to create a reference or test set from fresh non-human and embalmed human bone as substitute for human, and also to use the decision model for these deviating samples in practice.

Background: The increased use of virtual bone images in forensic anthropology requires a comprehensive study on the observational errors between dry bones and CT reconstructions. Here, we focus on the consistency of nonmetric sex estimation traits on the human skull.

Materials and methods: We scored nine nonmetric traits on dry crania and mandibles (n = 223) of archaeological origin and their CT reconstructions. Additionally, we 3D surface scanned a subsample (n = 50) and repeated our observations. Due to the intricate anatomy of the mental eminence, we split it into two separate traits: the bilateral mental tubercles and the midsagittal mental protuberance. We provide illustrations and descriptions for both these traits.

Results: We obtained supreme consistency values between the CT and 3D surface modalities. The most consistent cranial traits were the glabella and the supraorbital margin, followed by the nuchal crest, zygomatic extension, mental tubercles, mental protuberance, mental eminence, mastoid process and ramus flexure, in descending order. The mental tubercles show higher consistency scores than the mental eminence and the mental protuberance.

Discussion: The increased interchangeability of the virtual modalities with each other as compared to the dry bone modality could be due to the lack of tactility on both the CT and surface scans. Moreover, tactility appears less essential with experience than a precise trait description. Future studies could revolve around the most consistent cranial traits, combining them with pelvic traits from a previous study, to test for accuracy.

The grid and link search methods are used to recover scattered skeletal remains. Neither have not been compared robustly and clear guidelines for the link method have not been sufficiently developed. The study aimed to compare the effectiveness and efficiency of both methods and propose guidelines for the link method. The scattering patterns of two scavengers of forensic relevance-slender mongooses (Galerella sanguinea) and black-backed jackals (Canis mesomelas)-were recreated using four pig skeletons (Sus scrofa domesticus). Two groups (n = 6 each) were assigned a different method to recover the scattered remains. The length of the search and when each bone was located for each scatter pattern was recorded for each group and scatter pattern. A Likert scale questionnaire assessed participants' perceptions of their assigned method. A paired t-test (p = 0.005) compared the efficiency of each method and the questionnaire answers. Both methods were effective, recovering 100% of all remains. The link method was more efficient for both scatter patterns, despite there being no statistical significance (jackal: p = 0.089; mongoose: p = 0.464). Participants indicated favorable views for both methods; however, the link method scored significantly more favorably (p = 0.01) for efficiency. Specific guidelines were developed for the use of the link method. The link method is suggested for the recovery of scattered remains in forensic contexts, especially when the scavenger, its behavior, and scattering pattern is known or suspected.

In this study, we assessed the sexual dimorphism of the contemporary Japanese skull and established sex discriminant function equations based on cranial measurements using three-dimensional (3D) computed tomography (CT) images. The CT images of 263 corpses (142 males, 121 females) that underwent postmortem CT scanning and subsequent forensic autopsy were evaluated. Twenty-one cranial measurements were obtained from 3D CT reconstructed images, which extracted only bone data. We performed descriptive statistics and discriminant function analyses for the measurements. Nineteen measurements were significantly larger in males, suggesting sexual dimorphism of the Japanese skulls. Univariate discriminant function analyses using these measurements showed a sex classification accuracy of 57.8-88.2%, and bizygomatic breadth provided the highest correct prediction rate. Multivariate discriminant function analyses offered the most accurate model using seven variables with an estimation rate of 93.9%. Our results suggest that cranial measurements based on 3D CT images may help in the sex estimation of unidentified bodies in a contemporary Japanese population.

A questionnaire was prepared in advance of the 26th triennial conference of the International Academy of Legal Medicine (IALM) and sent to 474 email addresses included in the IALM mailing list. The questionnaire addressed three current challenges faced by the International Journal of Legal Medicine (IJLM): the publication of guidelines and validation studies in the field of legal medicine, the publication ethics of case reports, and the recruitment of new reviewers for the IJLM. The response rate was 20%. The survey results highlight the need for international guidelines in various areas of legal medicine. Some desired guidelines already exist. To provide visibility and knowledge of the existing national guidelines, the IJLM has launched a Topical Collection on Quality Assurance in Legal Medicine. This collection aims to inform readers about country-specific characteristics of legal medicine structures and the existing national guidelines.Around 80% of the participants stated that there are legal or ethical requirements for the publication of forensic case reports or case series. Various options for obtaining consent for publication are discussed. Eighty-six of the 97 participants indicated their willingness to review manuscripts for the IJLM. It is emphasized that the contributions of reviewers should be duly recognized and valued.

Background: Small amounts of DNA from a perpetrator collected during crime-scene investigations can be masked by large amounts of DNA from the victim. These samples can provide important information for the perpetrator's conviction. Short tandem repeat (STR) detection system is not sensitive enough to detect trace amounts of minor components in unbalanced mixed DNA. We developed a system using droplet digital polymerase chain reaction (ddPCR) capable of discovering trace components and accurately determining the ratio of mixed DNA in extremely unbalanced mixtures.

Methods: The non-recombining regions of the X chromosome and Y chromosome were quantified in the DNA of male and female mixtures using duplex ddPCR. Absolute quantification of low-abundance portions of trace samples and unbalanced mixtures was done using different mixing ratios.

Results: The ddPCR system could be used to detect low-abundance samples with < 5 copies of DNA components in an extremely unbalanced mixture at a mixing ratio of 10000:1. The high sensitivity and specificity of the system could identify the mixing ratio of mixed DNA accurately.

Conclusions: A ddPCR system was developed for evaluation of mixed samples of male DNA and female DNA. Our system could detect DNA quantities as low as 5 copies in extremely unbalanced mixed samples with good specificity and applicability. This method could assist forensic investigators in avoiding the omission of important physical evidence, and evaluating the ratio of mixed male/female trace samples.

Because emergency departments are often the first point of contact for victims of violence, it is critical to provide the appropriate treatment in compliance with all necessary medicolegal precautions. For this reason, a randomized controlled trial was conducted at the Policlinico Hospital of Milan (Italy) in which an intervention group (12 physicians) received a 6-h course on clinical forensic medicine and their performance in medicolegal procedures in claimed cases of violence was compared with that of a control group (13 physicians) by means of a 16-item assessment scale over the 3 months before and the 3 months after the course. Overall, 195 medical records were included in the statistical analysis. Out of these cases, 105 occurred before the course (60 analyzed by the control group and 45 by the intervention group) and 90 occurred after the course (45 analyzed by the control group and 45 by the intervention group). The results showed that the overall mean score of physicians who participated to the course increased from 14.0 (IQR 7.0) to 19.0 (IQR 8.0) with a p-value < 0.0001 and that the comparison between the intervention group and the control group after the course was 19.0 (IQR = 8.0) and 14.0 (IQR = 7.0), respectively, with a p-value < 0.0001. The improvement was very little and below the expectations pointing out that educational courses, although they can be a first step towards raising the ED physicians' awareness of clinical forensics, may not be enough and that more structured training and new strategies should be implemented.

The Lophophora genus of the Cactaceae family includes Lophophora diffusa and Lophophora williamsii, which has traditionally been used as a natural analgesic; however, its use is now under strict regulation worldwide as it contains mescaline, a unique psychotropic agent. Recently, non-medical and illegal distribution and abuse of L. williamsii have increased worldwide; thus, effective species identification methods are urgently needed. Here, we identified a new variable number tandem repeat (VNTR) marker in the trnL intron region to identify and characterize species in forensic analyses. The VNTR marker has a unique structure of tandem repeats, each with 13 nucleotides; one repeat unit was found in L. williamsii and two in L. diffusa. Phylogenetic and length polymorphism analyses confirmed that this novel VNTR marker could distinguish between Lophophora species. Furthermore, our newly developed TaqMan genotyping assay utilizes two probes; the color and position of dots on the discrimination plot differ according to the tandem repeat count within the VNTR marker. The limits of detection of the assay were 0.000063 ng (LW-VNTR probe-1) and 0.000066 ng (LW-VNTR probe-2), indicating high sensitivity. Moreover, when crime scene samples of 16 presumed L. williamsii species were analyzed, the results coincided with those of gas chromatography-mass spectrometry, confirming the applicability of our marker for Lophophora species identification. Thus, the tandem repeats within the trnL intron region can be exploited as a VNTR marker to identify L. williamsii and L. diffusa. Our dual TaqMan genotyping assay based on a novel marker demonstrates potential for forensic applications.

Protonitazene is a synthetic benzoimidazole opioid of the nitazenes class, developed in the 1950s as an effective analgesic, but never released in the market due to severe side effects and major risk of dependence. The laboratory was involved in the determination of the cause of death for 5 subjects deceased in a French department of the Indian Ocean. The 5 victims were male, aged between 20 and 35 years. The first 2 victims were found dead in their prison cell and the 3 other victims were found dead in a squat. Therefore, we have developed and validated a specific procedure to identify and quantify the drug in post mortem specimens using LC-MS/MS. The procedure involves extraction of 0.5 mL fluid at pH 9.5 with a mixture of organic solvents in presence of 20 ng fentanyl-d₅ used as internal standard. Linearity of the method was verified from 0.1 to 20 ng/mL in both whole blood and urine (r² = 0.9983 and 0.9993, respectively). The limit of detection was estimated at 0.05 ng/mL in each matrix. Protonitazene was identified at < LOQ to 0.8 ng/mL, 0.4 to 2.9 ng/mL and 3.0 to 8.0 ng/mL in femoral blood, urine and bile, respectively. Post mortem concentrations were very low, which is consistent with reported high toxicity of protonitazene. As nitazenes represent a growing threat to public health in various parts of the world, this method seems to be a good response to the challenges posed by the identification of this class of substances.

Dental Age Estimation (DAE) is an effective instrument of the rule of law for verifying dubious age claims in living individuals. Once tooth development is complete, only degenerative dental characteristics can be used for this purpose. The influence of ethnicity on these degenerative dental characteristics has not been clarified.Degenerative changes were examined using modified Gustafson's criteria including secondary dentin formation, cementum apposition, periodontal recession and attrition using the Olze et al. (2012) staging scales. Orthopantomograms of 1882 black South Africans, consisting of 934 females and 948 males, from 12.00 to 40.96 years of chronological age were utilized. Two independent examiners performed the evaluations, with one of the two evaluating all radiographs twice.The relationship between individual characteristics and chronological age was analyzed using multiple regression analysis with chronological age as the dependent variable. The resulting R² values ranged from 0.22 to 0.35, and the standard error of estimate were between 6.6 and 7.3 years. The correlation with age was consistently lower for females compared to males. The characteristic of cementum apposition emerged as critical in this population, due to a particularly low correlation with age and observer agreements partly in the "slight" range. The formula's values for the correlation with age were in general below the literature values for other populations. Overall, the limited precision of the age estimation by the formulae presented, especially for females, must be emphasized. The question of whether ethnicity per se exerts an influence on the characteristics in question, or whether the different socio-economic status, which encompasses factors such as nutrition and healthcare, is the determining factor, needs to be assessed in future studies.