PENDULUM--a guideline-based approach to the interpretation of STR mixtures

Several years ago, a theory to interpret mixed DNA profiles was proposed that included a consideration of peak area using the method of least squares. This method of mixture interpretation has not been widely adopted because of the complexity of the associated calculations. Most reporting officers (RO) employ an experience and judgement based approach to the interpretation of mixed DNA profiles. Here we present an approach that has formalised the thinking behind this experience and judgement. This has been written into a computer program package called PENDULUM. The program uses a least squares method to estimate the pre-amplification mixture proportion for two potential contributors. It then calculates the heterozygous balance for all of the potential sets of genotypes. A list of "possible" genotypes is generated using a set of heuristic rules. External to the programme the candidate genotypes may then be used to formulate likelihood ratios (LR) that are based on alternative casework propositions. The system does not represent a black box approach; rather it has been integrated into the method currently used by the reporting officers at the Forensic Science Service (FSS). The time saved in automating routine calculations associated with mixtures analysis is significant. In addition, the computer program assists in unifying reporting processes, thereby improving the consistency of reporting.     

Personality Pathways to Impulsive Behavior and Their Relations to Deviance: Results from Three Samples

The importance of the relation between impulsivity and deviance is well-acknowledged among criminologists. However, differences in the representations of impulsivity, some merely titular and others substantive, may cloud our understanding of these relations. The current study examines the argument, offered by Whiteside and Lynam Pers. Individuals Diff. (2000) 30: 669–689, that there may be four distinct personality pathways through which impulsive behavior may be manifested. Across three samples (two undergraduate, one community), we examine the validity of a four-factor structure of impulsivity, test whether these four pathways manifest divergent relations with various forms of deviant behavior such as crime and substance use, as well as laboratory manifestations of aggressive and impulsive behavior, and examine the invariance of these results across gender. The results support the existence of a four-factor model of impulsivity, the importance of two specific personality pathways in relation to self-reports of deviance (lack of premeditation and sensation seeking), as well as actual behavior, and suggest that these pathways are important for both men and women.     

Exploring the forensic use of the emotional recognition test (ERT)

General "hypo-emotionality" has now become a broadly accepted concept as one of the conspicuous psychological characteristics of repetitive, violent offenders. Numerous psychophysiological studies have verified this premise. The current study sought to examine the applicability of the Emotional Recognition Test (ERT) in a sample of 85 Korean inmates in a maximum-security prison. Two additional criterion groups were included for comparison: normal controls and schizophrenic inpatients. Because the ERT consists of problem-solving items, it is relatively free from response biases and is more efficient than measuring physiological responses. Results indicated that all criterion groups scored significantly differently on the ERT total and subscale scores. Additionally, similar to the physiological emotion-specific findings, emotion-specific subscales of the ERT indicated that offenders had significantly more difficulty in recognizing negative emotional stimuli, particularly sadness.     

Etiology of pulmonary thromboembolism in the absence of commonly recognized risk factors

Pulmonary thromboembolism is an often fatal complication of venous thrombosis. Any component or combination of the components composing Virchow's triad (venostasis, hypercoagulability, and endothelial damage) increases the propensity for a thrombophilic state. Hypercoagulable states may be inherited or acquired. While the etiology in many cases may be evident either on physical examination or on evaluation of the decedent's medical history, this is often not the case. We conducted a retrospective study of cases presenting to the Jefferson County Coroner/Medical Examiner's Office in Birmingham, Alabama, who were given a diagnosis of pulmonary embolism. A search of cases within the past 23 years yielded 81 cases. An underlying cause was determined in 70 cases (86%). The remaining 11 (14%) cases had no identifiable cause. We believe that a number of these cases may represent an underlying thrombophilic disorder. Since these disorders may be of an inherited or acquired nature, the determination of an etiology may be relevant to the decedent's family. Postmortem blood analyses may in selected cases be useful and appropriate for the detection of some of these disorders. However, such analyses are not practical in all cases, with each case having to be evaluated on its own merits.