Quantified Explosives Transfer on Surfaces for the Evaluation of Trace Detection Equipment

Trace explosive test surfaces are often required for the evaluation of trace detection equipment to determine the equipment performance. Test surfaces of C‐4, Detasheet, Semtex‐H, TNT, and HMTD were prepared by transferring trace amount of explosive deposited on polytetrafluoroethylene (PTFE) transfer strips onto different surfaces (Kraft paper, hard plastic, woven fabric, and soft vinyl). The amount of explosive transferred was deduced from the amount of explosive remaining on the PTFE strips after transfer, as quantified by direct analysis using tandem mass spectrometry with thermal desorption. From the data set of over 2000 transfers, we experienced lower transfer efficiency for Semtex‐H and Detasheet, and for soft vinyl and hard plastic. However, the rapid quantification mass spectrometric method allowed the transfer efficiency to be determined for all test surfaces used in an evaluation of trace explosive detectors, thereby permitting only the test surfaces with desired transfer to be accepted for the assessment.     

Evaluation of the IDS One-Step ELISA kits for the detection of illicit drugs in hair

This work presents the validation of a new immunological assay, the One-Step enzyme-linked immunosorbent assay (ELISA) tests from International Diagnostic Systems Corp. for the screening of drugs of abuse (cannabis, amphetamines, opiates, and cocaine) in human hair, with subsequent GC-MS confirmation. After decontamination and segmentation into small pieces, 50 mg of hair sample were incubated in 1 ml of methanol during 16 h at 40 degrees C. A 100 microL aliquot was collected and evaporated to dryness in presence of 100 microL of methanol/hydrochloric acid (99:1, v/v) to avoid amphetamines loss. The dried extract was dissolved in 100 microL of the "sample and standard diluent" solution included in the kit. This solution was submitted to analysis according to the recommended instructions of the manufacturer. During the validation phase, GC-MS confirmations were conducted according to our fully validated and published methods for opiates, cocaine, cannabis, and amphetamines determinations in hair. In a last development step, these procedures were slightly modified to directly confirm ELISA results by GC-MS using the methanolic extract. Ninety-three specimens were simultaneously screened by the ELISA tests (103 for tetrahydrocannabinol (THC)) and confirmed by GC-MS. Twenty were found positive for cannabis (THC: 0.10-6.50 ng/mg), 21 for cocaine (0.50-55.20 ng/mg), 24 for opiates (6-acetylmorphine (6-AM): 0.20-11.60 ng/mg, MOR: 0.20-8.90 ng/mg, codeine (COD): 0.20-5.90 ng/mg), and 13 for amphetamines (AP: 0.20 and 0.27 ng/mg, methamphetamine (MAP): 0.30 and 1.10 ng/mg, methylenedioxymethamphetamine (MDMA): 0.22-17.80 ng/mg). No false negative results were observed according to the Society of Hair Testing's (SoHT) cutoffs (0.5 ng/mg for cocaine, 0.2 ng/mg for opiates and amphetamines, and 0.1 ng/mg for THC). The One-Step ELISA kits appear suitable due to their sensitivity and specificity for drug of abuse screening in hair. This technology should find interest in workplace drug testing or driving license regranting, especially when many samples have to be tested with a high rate of negative samples, as ELISA is an easy and high-throughput method.     

Pattern detection in forensic case data using graph theory: application to heroin cutting agents

Pattern recognition techniques can be very useful in forensic sciences to point out to relevant sets of events and potentially encourage an intelligence-led style of policing. In this study, these techniques have been applied to categorical data corresponding to cutting agents found in heroin seizures. An application of graph theoretic methods has been performed, in order to highlight the possible relationships between the location of seizures and co-occurrences of particular heroin cutting agents. An analysis of the co-occurrences to establish several main combinations has been done. Results illustrate the practical potential of mathematical models in forensic data analysis.     

Complex Suicide by Self‐stabbing and Drowning: A Case Report and a Review of Literature

Sharp force injuries and drowning are methods exceptionally combined in complex suicides. We report a challenging case of complex suicide by self‐stabbing and drowning that illustrates the difficulty in discriminating between homicide and suicide in such circumstances of death. The corpse of a young man was found submerged in a river, stabbed nine times with two wounds that had penetrated the thorax and had caused lung injuries and a hemopneumothorax. The postmortem and histological examinations were consistent with a death caused by drowning, but the manner of death still remained undetermined. Police investigation finally concluded to a suicide, although no suicide note had been left and the victim had no underlying diagnosed mental disorder. The parameters that may help distinguish suicide from homicide at the autopsy should be interpreted in light of a thorough forensic investigation to determine the exact manner of death in such a case.     

Skull Fracture with Brain Expulsion in a One-Level Jumping-Fall

Abstract:  Here presented is the case of a one-level jumping-fall with extensive skull fractures and brain expulsion. The body was found on the basement floor at the foot of the stairs. At the autopsy, the skull was extensively fractured, with about half of the brain expulsed several feet away from the body. The cause of death was established as a craniocerebral trauma with brain expulsion. The circumstances and manner of death were still unclear at that time. A low fall seemed very unlikely considering the severity of the skull and brain damage. The police investigation clearly revealed that the man, in a paranoid psychotic state, attacked his wife with a knife and then was witnessed by his children to have hit his head several times with a hammer. Afterwards, they saw him running to the top of the basement stairs and jumping to the bottom of the stairs head first.     

The effect of police on crime,disorder and victim precaution. Evidence from a Dutch victimization survey

Using individual data from a large-scale Dutch crime victimization survey, we are able to expand the analysis of the effect of police on crime to crimes types that do not easily find their way into police statistics, and to public disorder and victim precaution. To address heterogeneity and simultaneity in the relation between police and crime, we model the police funding formula – used to distribute police resources across municipalities – to identify the endogenous variation in police levels. We use the remaining variation in police levels to identify the effect of police. We find significantly negative effects of higher police levels on property and violent crime, public disorder, and victim precaution. The effect on victim precaution is a hitherto largely ignored benefit of higher police levels not reflected in lower rates of crime and public disorder.     

Risk Factor Models for Adolescent Verbal and Physical Aggression Toward Fathers

Using a French-Canadian population-based longitudinal data set, we examine the impact of socioeconomic factors (paternal education and family structure); inherent individual factors (child gender and developmental trajectories of physical aggression from early to later childhood, problematic substance use), family environment (concurrent parent-child involvement, parental problematic substance use), and prospective and concurrent parenting process variables (mean parental supervision at puberty, concurrent punishment practices) as predictors of adolescent-directed aggression against fathers (in the last 6 months). A childhood behavioral pattern characterized by physical aggression showed the highest risk of adolescent-directed verbal and physical aggression toward fathers, regardless of sex. In terms of parental practices, verbal (and not corporal) punishment in the last 6 months significantly predicted aggression toward fathers. A childhood life-course of violence is likely to culminate in aggression toward fathers during adolescence. Beyond this risk, it seems that harsh verbal punishment by parents builds up the odds of child-directed aggression against fathers.     

Beyond law and order: Motives in the mobilization of the penal system

Résumé Cet article constitue une proposition théorique et méthodologique afin d'étudier les conditions menant à la mise en oeuvre du droit et, plus particulièrement, au déclenchement du processus pénal dans des situations concrètes. En utilisant de nombreux travaux empiriques et théoriques, les auteurs ont privilégié trois dimensions analytiques. Premièrement, les déterminants susceptibles d'affecter la mise en oeuvre du système pénal seront examinées. En deuxième lieu, une attention particulièrement sera accordée à l'identité des renvoyants. Enfin, les motifs à l'origine de la décision de renvoyer une affaire vers le système pénal seront discutés.