Prior to 1992, fire investigators generally examined fire scenes by subjective observation and a process of elimination. If no innocent cause could be determined, arson would be assumed. Arson was often concluded based on various fire pattern myths, for example, the belief that only the presence of an accelerant could result in "crazed glass" or spiderweb cracking. Such fire pattern myths were debunked in 1992 when NFPA 921 was published, disproving many myths and detailing the use of the scientific method. The present study was conducted to see whether fire pattern myths were still being mentioned in Canadian courts after 1992. Through a mixed methods study, 26 court case summaries ranging from 1979 to 2018 relating to arson were analyzed to identify the mention of fire pattern myths, negative corpus, placed accelerant or NFPA. Nine cases dated prior to and seventeen occurred after 1992. "Demarcation lines" and "multiple origins" in relation to accelerant placement were the most common and, were increasingly common after 1992. Avant 1992, les enqu & ecirc;teurs en incendie examinaient g & eacute;n & eacute;ralement les lieux d'incendie par observation subjective et par & eacute;limination. En l'absence de cause innocente, la piste criminelle & eacute;tait privil & eacute;gi & eacute;e. Cette conclusion reposait souvent sur diverses id & eacute;es re & ccedil;ues concernant les caract & eacute;ristiques d'un incendie, comme la croyance que seule la pr & eacute;sence d'un acc & eacute;l & eacute;rant pouvait expliquer le craquelage du verre ou les fissures en toile d'araign & eacute;e. Ces id & eacute;es re & ccedil;ues ont & eacute;t & eacute; d & eacute;menties en 1992 avec la publication de la norme NFPA 921, qui a r & eacute;fut & eacute; nombre d'entre elles et d & eacute;taill & eacute; l'application de la m & eacute;thode scientifique. La pr & eacute;sente & eacute;tude visait & agrave; d & eacute;terminer si ces id & eacute;es re & ccedil;ues & eacute;taient encore & eacute;voqu & eacute;es devant les tribunaux canadiens apr & egrave;s 1992. Au moyen d'une m & eacute;thodologie mixte, 26 r & eacute;sum & eacute;s de dossiers judiciaires relatifs & agrave; des incendies criminels, couvrant la p & eacute;riode de 1979 & agrave; 2018, ont & eacute;t & eacute; analys & eacute;s afin d'identifier toute mention de ces id & eacute;es re & ccedil;ues, de preuves n & eacute;gatives, d'acc & eacute;l & eacute;rant ou de la norme NFPA. Neuf cas dataient d'avant 1992 et dix-sept sont survenus apr & egrave;s. Les & laquo;lignes de d & eacute;marcation & raquo; et les & laquo;origines multiples & raquo; en lien avec le placement de l'acc & eacute;l & eacute;rateur & eacute;taient les plus fr & eacute;quentes et sont devenues de plus en plus courantes apr & egrave;s 1992.
Fatal insulin overdose remains a persistent diagnostic challenge in forensic practice, particularly when postmortem biochemical confirmation is limited or unavailable. This study retrospectively examined seven suicide deaths involving insulin-induced hypoglycemia adjudicated by the First Specialization Board of the Council of Forensic Medicine in Turkiye between 2011 and 2024. Case files, scene findings, psychiatric histories, insulin accessibility, toxicology data, and autopsy and histopathology reports were systematically reviewed. The decedents ranged from 30 to 81 years of age; four had diabetes mellitus requiring insulin therapy, while three had no therapeutic indication for insulin and obtained it through non-medical means. Most had documented suicidal behavior, and two had previously attempted self-harm specifically with insulin. Scene investigations frequently revealed insulin delivery devices, and vitreous glucose levels-when available-were low. Autopsy examinations demonstrated non-specific hypoxic-ischemic changes without pathognomonic indicators of insulin toxicity. Because postmortem biochemical instability and limited analytical capacity constrained insulin or analogue quantification, final determinations relied on a convergent evaluation integrating behavioral intent, access pathways, scene reconstruction, and exclusion of alternative causes. These findings underscore the importance of contextual medico-legal reasoning in classifying insulin-related deaths and provide a practical interpretive framework for situations in which toxicological confirmation is technically restricted.
Drug consumption is a recognized risk factor for morbidity and premature mortality worldwide. Toxicological findings in medico-legal death investigations provide important epidemiological insight into patterns of substance exposure within a population. This retrospective study aimed to characterize the prevalence and distribution of drugs detected in peripheral blood among decedents undergoing medico-legal autopsy in the B & iacute;o-B & iacute;o region of Chile between 2016 and 2020. Cases were identified from the regional office of the Servicio M & eacute;dico Legal. Decedents were included when at least one drug was detected and confirmed in peripheral blood. A total of 678 decedents had at least one drug detected during the study period. The most frequent certified causes of death were disease (29.2%), trauma (26.8%), asphyxia (15.0%), and suicide (10.6%). Men represented 82.6% of cases and women 17.4%. The most commonly detected substances were cocaine (45.7%), benzodiazepines (28.3%), and tetrahydrocannabinol (THC) (12.7%). Ages ranged from 1 to 96 years, with 84.5% of cases older than 31 years. Benzodiazepines and amitriptyline were more frequently detected among older decedents, whereas cocaine and THC predominated in younger age groups.
Infrared (IR) imaging techniques are widely used in forensic document analysis because they can reveal information invisible under normal lighting conditions. This study presents a method for determining the writing sequence of intersecting ballpoint pen strokes using a digital microscope and IR illumination. Many ballpoint pen inks became partially or fully transparent under IR illumination, enabling visualization of the physical grooves left by the rolling ball of the pen. By directing IR illumination at low angles, these grooves cast discernible shadows that revealed the spatial relationship between the overlapping strokes. At the intersections, the groove produced by the upper stroke disrupted or overlaid the underlying groove, enabling inference of the writing sequence. This approach is non-destructive, easy to implement, and highly reliable. Les techniques d'imagerie infrarouge (IR) sont largement utilis & eacute;es dans l'analyse m & eacute;dico-l & eacute;gale des documents, car elles permettent de r & eacute;v & eacute;ler des informations invisibles dans des conditions d'& eacute;clairage normales. Cette & eacute;tude pr & eacute;sente une m & eacute;thode permettant, & agrave; l'aide d'un microscope num & eacute;rique et d'un & eacute;clairage IR, de d & eacute;terminer la s & eacute;quence d'& eacute;criture des traits de stylo & agrave; bille qui se croisent. En effet, de nombreuses encres de stylo & agrave; bille deviennent partiellement ou totalement transparentes sous l'action de la lumi & egrave;re IR, ce qui permet de visualiser les rainures physiques laiss & eacute;es par le roulement de la bille du stylo. En orientant la lumi & egrave;re IR & agrave; faible angle sur ces rainures, nous obtenons des ombres discernables qui r & eacute;v & egrave;lent la relation spatiale entre les traits qui se chevauchent. & Agrave; chaque intersection, la rainure produite par le trait sup & eacute;rieur perturbe ou recouvre celle du trait inf & eacute;rieur, ce qui permet de d & eacute;duire la s & eacute;quence d'& eacute;criture. Cette approche est non destructive, facile & agrave; mettre en oe uvre et tr & egrave;s fiable.
When a body is exposed to the natural environment, there are a multitude of taphonomic agents that can affect the remains. One taphonomic agent that has not been extensively studied in Canada is vertebrate scavengers. Although in recent years vertebrate scavenging studies have occurred in several provinces, Canada is a large country with many environmental and climate types. This study aimed to determine the scavenger guild of a rural region of Leamington, in southwestern Ontario. Pig carcasses were surface deposited at a secure location which was accessible to scavengers with placement of two carcasses each in Fall 2023 and Summer 2024, respectively. Scavenging activity was captured using cellular and non-cellular trail cameras. Images were qualitatively analyzed to establish species interaction with the carcasses. It was found that the number of species was limited, but the presence of certain species was prevalent. At all sites, opossums and coyotes were the most frequent scavengers, with coyotes being responsible for the movement and dispersal of the carcasses. The study findings can provide valuable information when searching for human remains in this area or in other areas with similar terrain, climate and species. L'exposition d'un corps & agrave; l'environnement peut & ecirc;tre affect & eacute;e par divers facteurs taphonomiques, dont certains demeurent peu document & eacute;s au Canada, notamment l'influence des charognards vert & eacute;br & eacute;s. Malgr & eacute; quelques & eacute;tudes r & eacute;centes men & eacute;es dans certaines provinces, la diversit & eacute; des environnements et des climats & agrave; l'& eacute;chelle du pays n & eacute;cessite des recherches r & eacute;gionales suppl & eacute;mentaires. La pr & eacute;sente & eacute;tude vise & agrave; caract & eacute;riser la guilde des charognards dans une r & eacute;gion rurale de Leamington, au Sud-Ouest de l'Ontario. Quatre carcasses de porc ont & eacute;t & eacute; d & eacute;pos & eacute;es dans un site s & eacute;curis & eacute; accessible aux charognards: deux & agrave; l'automne 2023 et deux & agrave; l'& eacute;t & eacute; 2024. L'activit & eacute; des charognards a & eacute;t & eacute; enregistr & eacute;e & agrave; l'aide de cam & eacute;ras de chasse cellulaires et non cellulaires, puis analys & eacute;e qualitativement afin de documenter les interactions entre les charognards et les carcasses. Les r & eacute;sultats indiquent une diversit & eacute; d'esp & egrave;ces limit & eacute;e, mais une forte repr & eacute;sentation de certaines esp & egrave;ces. Les opossums et les coyotes ont & eacute;t & eacute; observ & eacute;s sur l'ensemble des sites et constituaient les charognards les plus actifs. Les coyotes ont exerc & eacute; l'influence la plus marqu & eacute;e sur le d & eacute;placement et la dispersion des carcasses. Ces r & eacute;sultats fournissent des renseignements essentiels utiles & agrave; la recherche de restes humains dans cette r & eacute;gion ou dans des environnements pr & eacute;sentant des conditions similaires en termes de climat, de terrain et d'esp & egrave;ces de charognards. Taphonomie Forensique, Charognards, Vert & eacute;br & eacute;s, D & eacute;composition, Sud-Ouest de l'Ontario
Male and female adults of Calliphora vicina (Robineau-Desvoidy) (Diptera: Calliphoridae) were exposed to different food sources and their food preferences were assessed. Each fly was colour-marked on their thorax; 20 flies were released at the same time in an arena where they were exposed to different food sources. The flies were filmed for six hours, and their preference was assessed based on the number of visits to a source and on the duration of each visit. This was calculated by multiplying the number of visits to a food source times the duration for each visit (NxL values). Significant differences were observed between males and females in their preferences of proteins versus carbohydrates; females preferred carbohydrate-rich foods, while males preferred protein-rich foods. These data could be useful for a better understanding of the nutritional ecology of blow flies and to better interpret entomological evidence at crime scenes where multiple potential food sources are present. Des adultes m & acirc;les et femelles de Calliphora vicina (Robineau-Desvoidy) (Diptera: Calliphoridae) ont & eacute;t & eacute; expos & eacute;s & agrave; diff & eacute;rentes sources de nourriture et leurs pr & eacute;f & eacute;rences alimentaires ont & eacute;t & eacute; & eacute;valu & eacute;es. Chaque mouche a & eacute;t & eacute; marqu & eacute;e d'une couleur sur le thorax; 20 mouches ont & eacute;t & eacute; l & acirc;ch & eacute;es en m & ecirc;me temps dans une ar & egrave;ne o & ugrave; elles ont & eacute;t & eacute; expos & eacute;es & agrave; diff & eacute;rentes sources de nourriture. Les mouches ont & eacute;t & eacute; film & eacute;es pendant six heures et leur pr & eacute;f & eacute;rence a & eacute;t & eacute; & eacute;valu & eacute;e en fonction du nombre de visites & agrave; une source et de la dur & eacute;e de chaque visite. Ceci a & eacute;t & eacute; calcul & eacute; en multipliant le nombre de visites & agrave; une source de nourriture par la dur & eacute;e de chaque visite (valeurs NxL). Des diff & eacute;rences significatives ont & eacute;t & eacute; observ & eacute;es entre les m & acirc;les et les femelles dans leurs pr & eacute;f & eacute;rences pour les prot & eacute;ines par rapport aux glucides ; les femelles pr & eacute;f & eacute;raient les aliments riches en glucides, tandis que les m & acirc;les pr & eacute;f & eacute;raient les aliments riches en prot & eacute;ines. Ces donn & eacute;es pourraient & ecirc;tre utiles pour mieux comprendre l'& eacute;cologie nutritionnelle des mouches bleues et pour mieux interpr & eacute;ter les preuves entomologiques sur les sc & egrave;nes de crime o & ugrave; plusieurs sources alimentaires potentielles sont pr & eacute;sentes.
Post-mortem interval (PMI) estimation is the first step in the investigation of decomposing remains. The absence of locally derived methods, and a dearth of forensic experts, make PMI estimation difficult in Nigeria. This study aimed to assess decomposition rates in southern Nigeria and to derive formulae for PMI estimation by using quantitative variables, accumulated degree days (ADD) and total body score (TBS), using a pig model (n = 20). A longitudinal examination of TBS and ADD was conducted over 14 months, during the dry and wet seasons. Scatter plots between TBS and PMI, and TBS and ADD were used to show decomposition patterns and loglinear random-effects maximum likelihood regression was used to produce linear regression formulae for PMI estimation. Overall, decomposition progressed rapidly. Shorter PMIs were associated with more advanced decomposition when compared to studies in temperate regions. Despite similar average daily temperatures in the wet and dry seasons, there were marked differences in decomposition patterns between the seasons, with the wet season exhibiting more rapid decomposition rates. This demonstrates the importance of rainfall and humidity in decomposition rates. The derived regression formulae for ADD and PMI will provide a much-needed location-specific method for PMI estimation in Nigeria and regions with similar climates. L'estimation de l'intervalle post mortem (IPM) est la premi & egrave;re & eacute;tape de l'examen des restes en d & eacute;composition. L'absence de m & eacute;thodes locales et le manque d'experts m & eacute;dico-l & eacute;gaux rendent difficile l'estimation de l'IPM au Nig & eacute;ria. Cette & eacute;tude avait pour objectif d'& eacute;valuer les taux de d & eacute;composition dans le sud du Nig & eacute;ria et de d & eacute;river des formules pour l'estimation de l'IPM & agrave; l'aide de variables quantitatives, des degr & eacute;s-jours cumul & eacute;s (DJC) et du score corporel total (SCT), en utilisant un mod & egrave;le porcin (n = 20). Un examen longitudinal du SCT et des DJC a & eacute;t & eacute; men & eacute; sur une p & eacute;riode de 14 mois, pendant les saisons s & egrave;che et humide. Des diagrammes de dispersion entre le SCT et l'IPM, et entre le SCT et les DJC ont & eacute;t & eacute; pour d & eacute;montrer les mod & egrave;les de d & eacute;composition, et une r & eacute;gression lin & eacute;aire al & eacute;atoire & agrave; effets maximaux a & eacute;t & eacute; utilis & eacute;e pour produire des formules de r & eacute;gression lin & eacute;aire pour l'estimation de l'IPM. Dans l'ensemble, la d & eacute;composition s'est av & eacute;r & eacute;e rapide. Des IPM plus courts ont & eacute;t & eacute; associ & eacute;s & agrave; une d & eacute;composition plus avanc & eacute;e par rapport & agrave; d'autres & eacute;tudes men & eacute;es dans des r & eacute;gions temp & eacute;r & eacute;es. M & ecirc;me si les temp & eacute;ratures quotidiennes moyennes & eacute;taient similaires pendant les saisons humides et s & egrave;ches, il existait des diff & eacute;rences notables dans les sch & eacute;mas de d & eacute;composition entre les saisons, la saison humide pr & eacute;sentant des taux de d & eacute;composition plus rapides. Cela d & eacute;montre l'importance des pr & eacute;cipitations et de l'humidit & eacute; dans le taux de d & eacute;composition. Des formules de r & eacute;gression lin & eacute;aire pour les DJC et l'IPM ont & eacute;t & eacute; d & eacute;riv & eacute;es et fourniront une m & eacute;thode adapt & eacute;e & agrave; chaque site, tr & egrave;s n & eacute;cessaire pour l'estimation de l'IPM au Nig & eacute;ria et dans les r & eacute;gions ayant des climats similaires.
Cam-type deformity of the hip is a morphological change at the femoral head-neck junction, caused by abnormal contact with the acetabulum during hip flexion. It can result from both pathological conditions and repetitive physical stress. Case presentation study examines skeletal remains of two individuals, Subjects A and B, both showing signs of cam-type deformity. Subject A exhibited osteogenesis imperfecta of the sternum, degenerative arthritis in the thoracic vertebrae and patellae, and partial fusion of adjacent vertebral bodies with hyperostosis. These findings suggest diffuse idiopathic skeletal hyperostosis (DISH), which likely caused altered gait mechanics and uneven weight distribution, contributing to the deformity. Subject B showed bilateral Achilles enthesopathy and early patellar hyperostosis, indicating a history of intense physical activity. The cam-type deformity in this case was attributed to overuse syndrome. Cam-type deformities can arise from distinct causes, including systemic pathology and mechanical overuse. Recognizing such skeletal changes can offer valuable insights into an individual's health and activity history, supporting efforts in forensic identification. La d & eacute;formation de type cam (ou bosse f & eacute;morale) de la hanche est une alt & eacute;ration morphologique de la jonction entre la t & ecirc;te f & eacute;morale et le col du f & eacute;mur. Elle se d & eacute;veloppe & agrave; la suite de mouvements de flexion de la hanche, en raison d'un contact anormal entre la cavit & eacute; ac & eacute;tabulaire et cette jonction t & ecirc;te-col. Des conditions tant pathologiques que physiologiques peuvent contribuer au d & eacute;veloppement de cette d & eacute;formation. La pr & eacute;sente & eacute;tude vise & agrave; examiner les restes osseux de deux individus, le sujet A et le sujet B, atteints d'une d & eacute;formation de type cam. Chez le sujet A, une ost & eacute;ogen & egrave;se imparfaite du sternum et une arthrose d & eacute;g & eacute;n & eacute;rative des vert & egrave;bres thoraciques et des rotules ont & eacute;t & eacute; observ & eacute;es. De plus, deux paires de corps vert & eacute;braux adjacents & eacute;taient presque fusionn & eacute;es, et une hyperostose & eacute;tait visible sur d'autres & eacute;l & eacute;ments vert & eacute;braux proches ainsi que sur les deux rotules. Chez le sujet B, une enth & eacute;sopathie du tendon d'Achille sur les calcan & eacute;ums droit et gauche ainsi qu'une hyperostose d & eacute;butante des rotules ont & eacute;t & eacute; observ & eacute;es. En cons & eacute;quence, on a pr & eacute;sum & eacute; que la d & eacute;formation de type cam chez le sujet A r & eacute;sultait d'une hyperostose squelettique idiopathique diffuse, entra & icirc;nant une biom & eacute;canique de la marche et une r & eacute;partition du poids corporelle alt & eacute;r & eacute;es. Chez le sujet B, la pr & eacute;sence d'une enth & eacute;sopathie du tendon d'Achille sugg & eacute;rait une activit & eacute; physique intense ant & eacute;rieure, et la d & eacute;formation de type cam aurait alors r & eacute;sult & eacute; d'un syndrome de surutilisation. Certaines activit & eacute;s physiques ou affections pathologiques associ & eacute;es & agrave; la d & eacute;formation de type cam peuvent fournir des informations pr & eacute;cieuses pour la reconstitution de l'identit & eacute; lors de la d & eacute;couverte de corps non identifi & eacute;s.
This study aimed to provide preliminary regionally-specific taphonomic data in Atlantic Canada using porcine analogues. Six adult porcine analogues were left outdoors to decompose naturally in late summer, sampled every three days to measure delta 13C and delta 15N in both skin and muscle over a total of twelve days. Over the course of the study, as porcine analogues transitioned through the fresh, bloat, and active decay stages of decomposition, delta 15Nmuscle became enriched from a mean starting value of 4.1 parts per thousand, first detectable at day-6 in the bloat phase by a mean change of similar to 0.5 parts per thousand. No such enrichments were found in delta 15Nskin, delta 13Cskin, or delta 13Cmuscle. This snapshot-in-time study provides important preliminary evidence that porcine muscle tissues become enriched in delta 15N as decomposition progresses and is detectable in the very early post-mortem interval. Future research can expand these findings to further elucidate the potential of stable isotopes as a quantifier of post-mortem interval in humans, and further taphonomic research in the under-studied region of Atlantic Canada.
The accessibility of 3D-printed firearms (3DPF) has increased in recent years, due in part to advancements in 3D printing technologies and a decrease in 3D-printer costs. The emergence of 3DPFs has raised security concerns, as their lack of serial numbers makes them difficult to trace. The province of Quebec is not spared by the rise of 3DPFs and has had to adapt to stay ahead. This paper presents data from all 3DPFs and 3D-printed related exhibits analyzed at the Laboratoire de sciences judiciaires et de m & eacute;decine l & eacute;gale (LSJML) from the first case identified in 2016 to 2023. Recently, a diversification of 3D-printed related exhibits has been observed. The most frequent 3DPF model received is a Glock-type frame which, once assembled, can perform as well as a commercial firearm. However, assembling any 3DPF can be challenging due to the time and parts needed to render it functional. An interdisciplinary team specializing in 3D-printed firearms was created at LSJML to develop its expertise and support the judicial system in its need for improvement in the forensic examination of 3DPFs. Finally, 3DPFs present challenges in court due to their novelty, as no consensus has been established on the required examination for these firearms.
Sex diagnosis by teeth is challenging in forensic cases in Mexico; it must involve the collaboration of experts to assist in the reconstructive identification process in cases where only dental evidence is available. Through a multidisciplinary approach (odontology, anthropology, and statistics), this study aims to analyze the reliability of mesiodistal (MD) distance in vestibular view at the incisal third in permanent canines from dental models with known data to generate a specific reference in the diagnosis sex for the Mexican population. Intra and interobserver tests of the measures recorded by four observers were used. Additionally, parametric statistical methods (descriptive statistics, confidence intervals, and logistic regression models) were employed to identify the relationship between distance and sex differences. The analysis demonstrated more significant dimorphism in the left maxillary and left and right mandibular canines, and results showed a 95% confidence interval; it was determined for the MD distances. Our study generates another tool to guide how to help discrimination between females and males (biological sex) in reconstructing the Mexican population's biological profile. This article proposes multidisciplinary forensic practice without the borders and delimited scope of each area; the identification of people in Mexico is a national problem that requires joint disciplines or team collaboration.
'Identification', where age and sex estimation are two main components, is one of the important issues of forensic medicine. In particular, sex estimation from skeletal remains and age estimation of unidentified people are frequently encountered. This study aimed to estimate age and sex with radiological imaging of the skull by evaluating cranial CT (computed tomography) images, cranial metric measurements frequently used in the literature, and paranasal sinus measurements. Using cranial CT images of 803 cases, 404 of whom were male (50.3%) and 399 of whom were female (49.7%), between the ages of 10-65, analyzed with PLS (partial least squares) regression model for age estimation, different models were created for sex estimation and statistical results were discussed with the literature. While only cranial metric measurements were able to correctly predict sex at a rate of 77% and only paranasal metric measurements at a rate of 70%, this rate increased to 79% when all measurements were used together. For age estimation, formulas were developed with the four parameters that we found to have the most statistically significant discriminatory power (nasal width, nasal height, right maxillary sinus width and left maxillary sinus depth).
Proficiency testing is required to ensure quality, efficiency, and safety in many disciplines. Multiple proficiency tests exist for forensic disciplines such as fingerprint analysis and toxicology, but minimal research has been conducted on the proficiency of crime scene experts. The foundation of an effective proficiency test rests upon the development of competency tests. Here, a proof-of-concept competency test was designed as an example of how to evaluate the crime scene processing skills of forensic identification officers (FIOs) using a mock crime scene scenario. The test has three main components: i) crime scene approach test, ii) evidence processing test, and iii) general crime scene knowledge test, with pre-test demographic questions. The competency testing content and process was reviewed by two forensic identification experts (manuscript co-authors) for viability. Due to its digital format, this competency test is widely accessible, user-friendly, and can be a template for a police service to develop their own crime scene competency test or an internal proficiency test for specialized tasks such as a fingerprint comparison or an estimation of the area origin in bloodstain pattern analysis (BPA) to help mitigate risks and identify knowledge gaps.
This research aimed to establish an accurate method of osteometric pair-matching calcanei in White, Black, and Coloured South Africans. Paired calcanei of 419 adult individuals (210 males, 209 females) were utilized. Both the left and right calcanei of 139 White South Africans (70 males, 69 females), 140 Black South Africans (70 males, 70 females), and 140 Coloured South Africans (70 males, 70 females) were examined. Six measurements were collected from each calcaneus. The variables that exhibited the least amount of directional and absolute asymmetry were maximum length (MAXL) and middle breadth (MIDB). The variables that exhibited greater degrees of directional and absolute asymmetry were articular facet dimensions (dorsal articular facet length (DAFL), dorsal articular facet breadth (DAFB), middle articular facet length (MAFL), and middle articular facet breadth (MAFB)). There were no statistically significant differences in directional and absolute asymmetry between sexes for most variables. There were statistically significant differences in absolute asymmetry between the three South African populations for some variables. Therefore, population-specific osteometric pair-matching methods are necessary. The statistic M was utilized to create reference tables for osteometric pair-matching. The values of M for MAXL for pair-matching comparisons resulted in the greatest reduction in the number of possible pairs with acceptable false rejection rates. The osteometric pair-matching tables from the current study can be utilized, in combination with visual pair-matching techniques, to assist in the resolution of commingled remains cases.
Residential fires continue to be a significant safety concern, especially as the majority are preventable. This study investigated 139 accidental residential fire deaths in Alberta between 2012 and 2021 to identify key characteristics and risk factors. The findings generally reinforce previous research on fatal accidental residential fires indicating that more deaths occurred amongst males (60.4%) than females (39.6%); seniors (65 and older) were found to be a high risk group; the majority of the fatal fires occurred in small population centres and rural areas (51.8%); alcohol consumption was prevalent among a large proportion of the decedents (46.7%); smoke inhalation was the leading cause of death (57.6%); a sizable number of fires occurred in the winter season (35.3%); a notable number of fires occurred during the 12am-6am time period (44.6%); and smoking material was the leading source of ignition in these residential fires (23%). The assessment of area-based deprivation in relation to fatal residential fires revealed that fatal fires were more frequent in communities with higher situational vulnerability and economic dependency. Les incendies r & eacute;sidentiels continuent & agrave; poser des probl & egrave;mes de s & eacute;curit & eacute; consid & eacute;rables, malgr & eacute; le fait que la majorit & eacute; sont & eacute;vitables. Cette & eacute;tude examine 139 d & eacute;c & egrave;s caus & eacute;s par des incendies r & eacute;sidentiels accidentels en Alberta entre 2020 et 2021 pour identifier les & eacute;l & eacute;ments d & eacute;clencheurs et les facteurs de risque. Les r & eacute;sultats sont en accord avec les & eacute;tudes pr & eacute;c & eacute;dentes sur les incendies r & eacute;sidentiels accidentels mortels, o & ugrave; que plus de d & eacute;c & egrave;s sont produits parmi les hommes (60.4 %) que les femmes (39.6 %); les personnes & acirc;g & eacute;es (65 +) sont un groupe & agrave; risque & eacute;lev & eacute;; la plupart des incendies mortels se sont d & eacute;roul & eacute;s dans de petites agglom & eacute;rations et des endroits ruraux (51.8 %); la consommation d'alcool & eacute;tait fr & eacute;quente parmi les d & eacute;funts (46.7 %); la cause principale de la mort & eacute;tait l'inhalation de fum & eacute;e (57.6 %); un nombre consid & eacute;rable d'incendies sont survenus durant l'hiver (35.3 %); plusieurs incendies ont eu lieu entre 0 h et 6 h (44.6 %); et les mat & eacute;riels & agrave; fumer & eacute;taient la cause principale d'ignition dans ces incendies r & eacute;sidentiels (23 %). L'& eacute;valuation des privations par zone en relation avec les incendies r & eacute;sidentiels mortels a r & eacute;v & eacute;l & eacute; que les incendies mortels & eacute;taient plus fr & eacute;quents dans les communaut & eacute;s ayant une situation de vuln & eacute;rabilit & eacute; et une d & eacute;pendance & eacute;conomique plus & eacute;lev & eacute;e.
This article re-evaluates the results of a controlled drinking study done in Germany to determine inter-subject variation in the blood-to-breath ratio (BBR) of alcohol. Statutory blood-alcohol concentration (BAC) limits for driving in Germany are 0.50 g/kg (administrative offence) and 1.1 g/kg (criminal offence). Mass/mass concentration units (g/kg) are 6 % lower than mass/volume (g/L) units, because the density of blood is 1.06 kg/L on average. The corresponding statutory breath-alcohol concentration (BrAC) limits for driving in Germany are 0.25 mg/L and 0.55 mg/L, respectively. BAC in road traffic cases is determined indirectly by the analysis of serum and dividing by 1.236, which underestimates the true BAC. Using Alcotest 9510 DE evidential breath analyzer, the mean +/- SD, median and range of BBRs of alcohol were 2047 +/- 150, 2053, and 1571-2394 and 61% were less than 2100:1. After re-calculating BAC assuming a serum/blood distribution ratio of ethanol of 1.14:1 and reporting results in mass/volume units, the corresponding BBRs were 2220 +/- 162, 2226, and 1703-2595 and 21% were less than 2100. Care is needed when the results of German studies of the BBR of alcohol are compared and contrasted with studies done in other countries. Cet article r & eacute;& eacute;value les r & eacute;sultats d'une & eacute;tude sur la consommation contr & ocirc;l & eacute;e d'alcool r & eacute;alis & eacute;e en Allemagne afin de d & eacute;terminer la variation inter-sujets du rapport sang-haleine (RSA) de l'alcool. Les limites l & eacute;gales de concentration d'alcool dans le sang (BAC) pour la conduite en Allemagne sont de 0,50 g/kg (infraction administrative) et de 1,1 g/kg (infraction p & eacute;nale). Les unit & eacute;s de concentration masse/masse (g/kg) sont inf & eacute;rieures de 6 % aux unit & eacute;s masse/volume (g/L), car la densit & eacute; du sang est de 1,06 kg/L en moyenne. Les limites l & eacute;gales correspondantes de concentration d'alcool dans l'air expir & eacute; (BrAC) pour la conduite en Allemagne sont respectivement de 0,25 mg/L et 0,55 mg/L. Le taux d'alcool & eacute;mie dans les cas de trafic routier est d & eacute;termin & eacute; indirectement en analysant le s & eacute;rum et en le divisant par 1,236, ce qui sous-estime le taux d'alcool & eacute;mie r & eacute;el. En utilisant l'analyseur d'haleine Alcotest 9510 DE, la moyenne +/- SD, la m & eacute;diane et l'intervalle des taux d'alcool & eacute;mie & eacute;taient de 2047 +/- 150, 2053, et 1571-2394 et 61% d'entre eux & eacute;taient inf & eacute;rieurs & agrave; 2100:1. Apr & egrave;s avoir recalcul & eacute; l'alcool & eacute;mie en supposant un rapport de distribution s & eacute;rum/sang de l'& eacute;thanol de 1,14:1 et rapport & eacute; les r & eacute;sultats en unit & eacute;s masse/volume, les TBC correspondants & eacute;taient de 2220 +/- 162, 2226, et 1703-2595 et 21% & eacute;taient inf & eacute;rieurs & agrave; 2100. Il convient d'& ecirc;tre prudent lorsque les r & eacute;sultats des & eacute;tudes allemandes sur le TBC de l'alcool sont compar & eacute;s et mis en contraste avec des & eacute;tudes r & eacute;alis & eacute;es dans d'autres pays.
One method of estimating the post mortem interval (PMI) is to use the oldest stage of immature blow flies on or surrounding a corpse to determine the minimum PMI. When finished feeding, larvae leave a carcass to pupate in the surrounding soil, and can be difficult to find. We investigated if flat and undulating terrain affect how far Lucilia illustris larvae disperse after feeding. We hypothesized that post-feeding larvae disperse over undulating and flat terrain about the same travel distance. However, because larvae must crawl up and downhill in undulating terrain they end up pupating in soil closer to the originating carcass than larvae that crawled over flat terrain. We tested this in a field study using pig half-heads placed on sand which had two surface treatments, flat sand and sand with 2.5 cm undulations. We allowed blow flies to lay eggs on the half-heads, took soil core samples at various distances, then allowed adults to emerge in the lab. In undulating terrain, while more adults emerged from soil cores closer to carcasses than from soil core from flat terrain. However, net travel path lengths were similar for both treatments.
There are limited options reported for the detection of footwear impressions in ice melt products. Enhancement of footwear impressions in ice melt products using a fluorescent metal-organic complex was identified in this work. The deprotonation of 8-hydroxyquinoline with a solution of strong base led to the formation of a complex between calcium and magnesium ions commonly found in winter ice melt products. Three ice melt products containing 0.01-99% calcium were compared for enhancement with 8-hydroxyquinoline reagent. With 254 nm light, footwear impressions enhanced with this method fluoresced on a semi-porous tile surface. This application of 8-hydroxyquinoline is a simple, efficient method to enhance footwear impressions, and offers a stable alternative reagent compared to the acetone solution used in previous work. Les options rapportees sur la detection des impressions de chaussures dans les produits de fonte de glace sont limitees. Ce travail a permis de mettre en evidence l'amelioration des impressions de chaussures dans les produits de fonte de glace a l'aide d'un complexe metal-organique fluorescent. La deprotonation de la 8-hydroxyquinoline avec une solution de base forte a conduit a la creation d'un complexe entre les ions de calcium et de magnesium que l'on trouve couramment dans les produits de fonte de glace d'hiver. Trois produits de fonte de glace contenant de 0,01 a 99 % de calcium ont ete compares pour l'amelioration avec le reactif 8-hydroxyquinoline. Avec une lumiere de 254 nm, les impressions de chaussures ameliorees par cette methode sont devenues fluorescentes sur la surface d'un carreau semi-poreux. Cette application de la 8-hydroxyquinoline est une methode simple et efficace pour ameliorer les impressions de chaussures et elle offre un reactif alternatif stable par rapport a la solution d'acetone trouvee dans les travaux precedents.
