853 resultados para Forensic chemistry
Resumo:
Adrenaline (epinephrine) auto-injectors provide life-saving pre-hospital treatment for individuals experiencing anaphylaxis in a community setting. Errors in handling adrenaline auto-injectors, particularly by children and healthcare professionals, have been reported. Reports of adrenaline overdoses are limited in the medical literature. In most of these cases, accidental adrenaline administration results from medical error. Exogenous administration of catecholamine is responsible for cardiovascular and metabolic responses, which may cause supraventricular tachycardia, ventricular dysrhythmias and myocardial ischemia. The authors present a unique autopsy case involving a 34 year-old woman who intentionally self-injected adrenaline using an adrenaline auto-injector as part of a suicide plan. Catecholamines and metanephrines were measured in peripheral and cardiac blood as well as urine and vitreous humor. Based on the results of all postmortem investigations, the cause of death was determined to be cardiac dysrhythmia and cardiac arrest following adrenaline self-injection.
Resumo:
PURPOSE: The goal of the study was to assess the causes and analyze the cases of sudden cardiac death (SCD) victims referred to the department of forensic medicine in Lausanne, with a particular focus on sports-related fatalities including also leisure sporting activities. To date, no such published assessment has been done nor for Switzerland nor for the central Europe. METHODS: This is a retrospective study based on autopsy records of SCD victims, from 10 to 50 years of age, performed at the University Centre of Legal Medicine in Lausanne from 1995 to 2010. The study population was divided into two groups: sport-related (SR) and not sport-related (NSR) SCDs. RESULTS: During the study period, 188 cases of SCD were recorded: 166 (88%) were NSR and 22 (12%) SR. The mean age of the 188 victims was 37.3 ± 10.1 years, with the majority of the cases being male (79%). A cause of death was established in 84%, and the pathology responsible for death varied according to the age of the victims. In the NSR group, the mean age was 38.2 ± 9.2 years and there was 82% of male. Coronary artery disease (CAD) was the main diagnosis in the victims aged 30-50 years. The majority of morphologically normal hearts were observed in the 15-29 year age range. There was no case in the 10-14 year age range. In the SR group, 91% of victims died during leisure sporting activities. In this group the mean age was 30.5 ± 13.5 years, with the majority being male (82%). The main cause of death was CAD, with 6 cases (27%) and a mean age of 40.8 ± 5.5 years. The youngest victim with CAD was 33 years old. A morphologically normal heart was observed in 5 cases (23%), with a mean age of 24.4 ± 14.9 years. The most frequently implicated sporting activities were hiking (26%) and swimming (17%). CONCLUSION: In this study, CAD was the most common cause of death in both groups. Although this pathology most often affects adults over 35 years of age, there were also some victims under 35 years of age in both groups. SCDs during sport are mostly related to leisure sporting activities, for which preventive measures are not yet usually established. This study highlights also the need to inform both athletes and non athletes of the cardiovascular risks during sport activities and the role of a forensic autopsy and registries involving forensic pathologists for SR SCD.
Resumo:
AIM: The aim of our study was to compare traumatic injuries observed after cardiopulmonary resuscitation (CPR) by means of standard (manual) or assisted (mechanical) chest compression by Lund University Cardiopulmonary Assist System, 2nd generation (LUCAS?2) device. METHODS: A retrospective study was conducted including cases from 2011 to 2013, analysing consecutive autopsy reports in two groups of patients who underwent medicolegal autopsy after unsuccessful CPR. We focused on traumatic injuries from dermal to internal trauma, collecting data according to a standardised protocol. RESULTS: The study group was comprised of 26 cases, while 32 cases were included in the control group. Cardiopulmonary resuscitation performed by LUCAS?2 was longer than manual CPR performed in control cases (study group: mean duration 51.5 min; controls 29.4 min; p = 0.004). Anterior chest lesions (from bruises to abrasions) were described in 18/26 patients in the LUCAS?2 group and in 6/32 of the control group. A mean of 6.6 rib fractures per case was observed in the LUCAS?2 group, but this was only 3.1 in the control group (p = 0.007). Rib fractures were less frequently observed in younger patients. The frequency of sternal factures was similar in both groups. A few trauma injuries to internal organs (mainly cardiac, pulmonary and hepatic bruises), and some petechiae (study 46 %; control 41 %; p = 0.79) were recorded in both groups. CONCLUSION: LUCAS?2-CPR is associated with more rib fractures than standard CPR. Typical round concentric skin lesions were observed in cases of mechanical reanimation. No life-threatening injuries were reported. Petechiae were common findings.
Resumo:
This paper is concerned with the contribution of forensic science to the legal process by helping reduce uncertainty. Although it is now widely accepted that uncertainty should be handled by probability because it is a safeguard against incoherent proceedings, there remain diverging and conflicting views on how probability ought to be interpreted. This is exemplified by the proposals in scientific literature that call for procedures of probability computation that are referred to as "objective," suggesting that scientists ought to use them in their reporting to recipients of expert information. I find such proposals objectionable. They need to be viewed cautiously, essentially because ensuing probabilistic statements can be perceived as making forensic science prescriptive. A motivating example from the context of forensic DNA analysis will be chosen to illustrate this. As a main point, it shall be argued that such constraining suggestions can be avoided by interpreting probability as a measure of personal belief, that is, subjective probability. Invoking references to foundational literature from mathematical statistics and philosophy of science, the discussion will explore the consequences of this interdisciplinary viewpoint for the practice of forensic expert reporting. It will be emphasized that-as an operational interpretation of probability-the subjectivist perspective enables forensic science to add value to the legal process, in particular by avoiding inferential impasses to which other interpretations of probability may lead. Moreover, understanding probability from a subjective perspective can encourage participants in the legal process to take on more responsibility in matters regarding the coherent handling of uncertainty. This would assure more balanced interactions at the interface between science and the law. This, in turn, provides support for ongoing developments that can be called the "probabilization" of forensic science.
Resumo:
A growing body of scientific literature recurrently indicates that crime and forensic intelligence influence how crime scene investigators make decisions in their practices. This study scrutinises further this intelligence-led crime scene examination view. It analyses results obtained from two questionnaires. Data have been collected from nine chiefs of Intelligence Units (IUs) and 73 Crime Scene Examiners (CSEs) working in forensic science units (FSUs) in the French speaking part of Switzerland (six cantonal police agencies). Four salient elements emerged: (1) the actual existence of communication channels between IUs and FSUs across the police agencies under consideration; (2) most CSEs take into account crime intelligence disseminated; (3) a differentiated, but significant use by CSEs in their daily practice of this kind of intelligence; (4) a probable deep influence of this kind of intelligence on the most concerned CSEs, specially in the selection of the type of material/trace to detect, collect, analyse and exploit. These results contribute to decipher the subtle dialectic articulating crime intelligence and crime scene investigation, and to express further the polymorph role of CSEs, beyond their most recognised input to the justice system. Indeed, they appear to be central, but implicit, stakeholders in intelligence-led style of policing.
Resumo:
Here we present results of studies conducted by the Research Unit of Legal Psychiatry and Psychology of Lausanne about risk assessment and protective factors in the evaluation of violence recidivism. It aims to help experts in considering the relevance and use of tools at their disposal. Particular attention is given to the significance of protective factors and impulsive dimensions, as to the inter-raters process that leads to the final deliberations.
Resumo:
This paper presents a preliminary study on the degradation of spray paint samples, illustrated by Optical, FTIR and Raman measurements. As opposed to automotive paints which are specifically designed for improved outdoor exposure and protected using hindered amine light absorbers (HALS) and ultra-violet absorbers (UVA), the spray paints on their side are much simpler in composition and very likely to suffer more from joint effects of solar radiation, temperature and humidity. Six different spray paint were exposed to outdoor UV-radiation for a total period of three months and both FTIR and Raman measurements were taken systematically during this time. These results were later compared to an artificial degradation using a climate chamber. For infrared spectroscopy, degradation curves were plotted using the photo-oxidation index (POI), and could be successfully approximated with a logarithmic fitting (R2 > 0.8). The degradation can appear after the first few days of exposure and be important until 2 months, where it stabilizes and follow a more linear trend afterwards. One advantage is that the degradation products appeared almost exclusively at the far end (∼3000 cm−1) of mid-infrared spectra, and that the fingerprint region of the spectra remained stable over the studied period of time. Raman results suggest that the pigments on the other side, are much more stable and have not shown any sign of degradation over the time of this study. Considering the forensic implications of this environmental degradation, care should be taken when comparing samples if weathering is an option (e.g. an exposed graffiti compared to the paint from a fresh spray paint can). Degradation issues should be kept in mind as they may induce significant differences between paint samples of common origin.
Resumo:
The late president of the Palestinian Authority, Yasser Arafat, died in November 2004 in Percy Hospital, one month after having experienced a sudden onset of symptoms that included severe nausea, vomiting, diarrhoea and abdominal pain and which were followed by multiple organ failure. In spite of numerous investigations performed in France, the pathophysiological mechanisms at the origin of the symptoms could not be identified. In 2011, we found abnormal levels of polonium-210 ((210)Po) in some of Arafat's belongings that were worn during his final hospital stay and which were stained with biological fluids. This finding led to the exhumation of Arafat's remains in 2012. Significantly higher (up to 20 times) activities of (210)Po and lead-210 ((210)Pb) were found in the ribs, iliac crest and sternum specimens compared to reference samples from the literature (p-value <1%). In all specimens from the tomb, (210)Po activity was supported by a similar activity of (210)Pb. Biokinetic calculations demonstrated that a (210)Pb impurity, as identified in a commercial source of 3MBq of (210)Po, may be responsible for the activities measured in Arafat's belongings and remains 8 years after his death. The absence of myelosuppression and hair loss in Mr Arafat's case compared to Mr Litvinenko's, the only known case of malicious poisoning with (210)Po, could be explained by differences in the time delivery-scheme of intake. In conclusion, statistical Bayesian analysis combining all the evidence gathered in our forensic expert report moderately supports the proposition that Mr Arafat was poisoned by (210)Po.
Resumo:
Many people regard the concept of hypothesis testing as fundamental to inferential statistics. Various schools of thought, in particular frequentist and Bayesian, have promoted radically different solutions for taking a decision about the plausibility of competing hypotheses. Comprehensive philosophical comparisons about their advantages and drawbacks are widely available and continue to span over large debates in the literature. More recently, controversial discussion was initiated by an editorial decision of a scientific journal [1] to refuse any paper submitted for publication containing null hypothesis testing procedures. Since the large majority of papers published in forensic journals propose the evaluation of statistical evidence based on the so called p-values, it is of interest to expose the discussion of this journal's decision within the forensic science community. This paper aims to provide forensic science researchers with a primer on the main concepts and their implications for making informed methodological choices.
Resumo:
The aim of this study is to provide an effective and quick reference guide based on the most useful European formulae recently published for subadult age estimation. All of these formulae derive from studies on postnatal growth of the scapula, innominate, femur, and tibia, based on modern skeletal data (173 ♂, 173 ♀) from five documented collections from Spain, Portugal, and Britain. The formulae were calculated from Inverse Regression. For this reason, these formulae are especially useful for modern samples from Western Europe and in particular on 20th century human remains from the Iberian Peninsula. Eleven formulae were selected as the most useful because they can be applied to individuals from within a wide age range and in individuals of unknown sex. Due to their high reliability and because they derive from documented European skeletal samples, we recommend these formulae be used on individuals of Caucasoid ancestry from Western Europe.
Resumo:
Introduction: The Violence Medical Unit (VMU), a specialised forensic medical consultation, was created at the Lausanne university Hospital in 2006. All patients consulting at the ED for interpersonal violencerelated injury are referred to the VMU, which provides forensic documentation of the injury and referral to the relevant community based victim-support organisations within 48 hours of the ED visit. This frees the ED medical staff from forensic injury documentation and legal/social referral, tasks for which they lack both time and training. Among community violence, assaults by nightclub security agents against patrons have increased from 6% to 10% between 2007 and 2009. We set out to characterise the demographics, assault mechanisms, subsequent injuries, prior alcohol intake and ED & VMU costs incurred by this group of patients. Methods: We retrospectively included all patients consulting at the VMU due to assault by nightclub security agents from January 2007 to December 2009. Data was obtained from ED & VMU medical, nursing and administrative records. Results: Our sample included 70 patients, of which 64 were referred by the CHUV ED. The victims were typically young (median age 29) males (93%). 77% of assaults occurred on the weekend between 12 PM and 4 AM, and 73% of the victims were under the influence of alcohol. 83% of the patients were punched, kicked and/or head-butted; 9% had been struck with a blunt instrument. 80% of the injuries were in the head and neck area and 19% of the victims sustained fractures. 21% of the victims were prescribed medical leave. Total ED & VMU costs averaged 1048 SFr. Conclusion: Medical staff treating this population of assault victims must be aware of the assault mechanisms and injury patterns, in particular the high probability of fractures, in order to provide adequate diagnosis and care. Associated inebriation mandates liberal use of radiology, as delayed or missed diagnosis may have medical, medicolegal and legal implications. Emergency medical services play an important role in detecting and reporting of such incidents. Centralised management of the forensic documentation facilitates referral to victim support organisations and epidemiological data collection. Magnitudes and trends of the different types of violence can be determined, and this information can be then impact public safety management policies.
Resumo:
Following their detection and seizure by police and border guard authorities, false identity and travel documents are usually scanned, producing digital images. This research investigates the potential of these images to classify false identity documents, highlight links between documents produced by a same modus operandi or same source, and thus support forensic intelligence efforts. Inspired by previous research work about digital images of Ecstasy tablets, a systematic and complete method has been developed to acquire, collect, process and compare images of false identity documents. This first part of the article highlights the critical steps of the method and the development of a prototype that processes regions of interest extracted from images. Acquisition conditions have been fine-tuned in order to optimise reproducibility and comparability of images. Different filters and comparison metrics have been evaluated and the performance of the method has been assessed using two calibration and validation sets of documents, made up of 101 Italian driving licenses and 96 Portuguese passports seized in Switzerland, among which some were known to come from common sources. Results indicate that the use of Hue and Edge filters or their combination to extract profiles from images, and then the comparison of profiles with a Canberra distance-based metric provides the most accurate classification of documents. The method appears also to be quick, efficient and inexpensive. It can be easily operated from remote locations and shared amongst different organisations, which makes it very convenient for future operational applications. The method could serve as a first fast triage method that may help target more resource-intensive profiling methods (based on a visual, physical or chemical examination of documents for instance). Its contribution to forensic intelligence and its application to several sets of false identity documents seized by police and border guards will be developed in a forthcoming article (part II).
Resumo:
The evaluation of forensic evidence can occur at any level within the hierarchy of propositions depending on the question being asked and the amount and type of information that is taken into account within the evaluation. Commonly DNA evidence is reported given propositions that deal with the sub-source level in the hierarchy, which deals only with the possibility that a nominated individual is a source of DNA in a trace (or contributor to the DNA in the case of a mixed DNA trace). We explore the use of information obtained from examinations, presumptive and discriminating tests for body fluids, DNA concentrations and some case circumstances within a Bayesian network in order to provide assistance to the Courts that have to consider propositions at source level. We use a scenario in which the presence of blood is of interest as an exemplar and consider how DNA profiling results and the potential for laboratory error can be taken into account. We finish with examples of how the results of these reports could be presented in court using either numerical values or verbal descriptions of the results.