Two items of evidence, no putative source: an inference problem in forensic intelligence

Intelligence analysts commonly associate cases on the basis of similarities found in compared characteristics of scientific evidence. The present paper studies some of the inferential difficulties associated with such operations. An analysis is proposed that breaks down the reasoning process into inference to common source, and inference to case linkage. The former requires an approach to the difficulty associated with evaluating the similarities of items of evidence from different cases with no putative source being available. The latter requires consideration to be given to the relevance of evidence. Throughout the paper, probability theory is used to describe the nature of the proposed inferences. Graphical models are also introduced with the aim of providing further insight into the dependence and independence relationships assumed to hold among the various propositions considered. Notions from decision theory are used to discuss ways in which intelligence analysts may assist investigators in deciding whether or not cases should be considered as linked.     

Histopathological findings in 851 autopsies of drug addicts, with toxicologic and virologic correlations

This investigation was carried out on 851 consecutive judicial autopsies of drug addicts who died mostly of heroin overdose from 1977 to 1996. Research of anti-HIV/HBV/HCV antibodies was performed, and histologic sections were retrospectively reviewed. More than 65% were HBV/HCV-positive and about 17% HIV-positive; females were HIV-positive more often than males. Intracranial microhemorrhages were frequently found; cerebral infectious diseases were rare. Inflammatory heart lesions, myocardial fibrosis, and acute ischemia were common. Interstitial nephritis (found in about 8%) was more frequent in females, in older patients, and in those carrying HIV infection; glomerular sclerosis was detected in about 12%. Acute bronchitis and/or pneumonia was demonstrated in 12%, without significant association with HIV infection; pulmonary hemorrhages, foreign body granulomas, and food aspiration were also commonly seen; hyperplasia of pulmonary perivascular lymphatic tissue was rather characteristic. Liver was carrying steatosis in 66.3% and/or hepatitis in 64.5%; acute hepatitis was more frequent in females, chronic hepatitis in older subjects and in those proven positive for hepatotropic viruses; cirrhosis occurred more often in older patients, in those carrying virus infection, and in consumers of nonnarcotics drugs such as ethanol. No pathologic finding was clearly related to drug abuse; therefore, during autopsy, drug addiction can be suspected, but anamnestic and circumstantial data are needed to lead pathologists to request toxicologic analysis to ascertain the cause of death. The present investigation emphasizes that, in addition to the risk of death by overdose, the high incidence of acute and chronic diseases could seriously undermine the health status of heroin and/or other drug consumers.     

Apnea, glial apoptosis and neuronal plasticity in the arousal pathway of victims of SIDS

Of 27,000 infants whose sleep-wake characteristics were studied under the age of 6 months, 38 died unexpectedly 2-12 weeks after the sleep recording in a pediatric sleep laboratory. Of these infants, 26 died of sudden infant death syndrome (SIDS), and 12 of definitely identified causes. The frequency and duration of sleep apneas were analysed. Sleep recordings and brainstem histopathology were studied to elucidate the possible relationship between sleep apnea and neuropathological changes within the arousal system. Immunohistochemical analyses were conducted using tryptophan hydroxylase (TrypH), a serotonin synthesizing enzyme, and growth-associated phosphoprotein 43 (GAP43), a marker of synaptic plasticity. The terminal-deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) method was used for apoptosis. The pathological and physiological data were correlated for each infant. In the SIDS victims, statistically significant positive correlations were seen between the number of TrypH-positive neurons in the dorsal raphe nucleus of the midbrain and the duration of central apneas (p = 0.03), between the number of TUNEL-positive glial cells in the pedunculopontine tegmental nucleus (PPTN) and the average number of spines in GAP43-positive neurons in the PPTN (p = 0.04). These findings in the dorsal raphe nucleus of the midbrain and PPTN, that play important roles in the arousal pathway suggest a possible link between changes in arousal and SIDS.     

Delay of clinical manifestation and medical malpractice in a serious vascular complication of proximal locked tibial nailing

We are reporting on a case of complex lesion of the popliteal neurovascular bundle in a young woman, resulting from an operation for reduction and synthesis of a closed spiroid fracture of the mid-distal third of the left tibia by means of a Grosse-Kempf nail, with significant delay of clinical manifestation. Determining whether this is an "unavoidable complication" or "medical malpractice" is the target of the forensic investigation. In this case, the investigation leads to the conclusion that medical malpractice was the only explanation of the damage.     

Minor or adult? Introducing decision analysis in forensic age estimation

Nowadays, forensic age estimation takes an important role in worldwide forensic and medico-legal institutes that are solicited by judicial or administrative authorities for providing an expert report on the age of individuals. The authorities’ ultimate issue of interest is often the probability that the person is younger or older than a given age threshold, which is usually the age of majority. Such information is fundamental for deciding whether a person being judged falls under the legal category of an adult. This is a decision that may have important consequences for the individual, depending on the legal framework in which the decision is made. The aim of this paper is to introduce a normative approach for assisting the authority in the decision-making process given knowledge from available findings reported by means of probabilities. The normative approach proposed here has been acknowledged in the forensic framework, and represents a promising structure for reasoning that can support the decision-making process in forensic age estimation. The paper introduces the fundamental elements of decision theory applied to the specific case of age estimation, and provides some examples to illustrate its practical application.