Composite Machine Learning Algorithm for Material Sourcing,

This study developed a composite machine learning algorithm for attribution of materials of forensic interest (like ammonium nitrate) to original sources. k-nearest neighbor and random forest models were used for source elimination and classification, respectively, in a two-step, composite algorithm based on particle color, size/shape, and trace element concentration features. Novel approaches for simulation to supplement within-source reference features based on empirically measured multi-lot analyses, an improved hold-one-lot-out method for cross-validation, an assessment of the likelihood of the presence of a reference sample, fusion of the source probabilities from the respective classification models, and the calculation of metrics for assessing ensemble sourcing performance are described. Excellent sourcing predictions were obtained; the sourcing algorithm identified the correct source as the top choice 89% of the time, and the correct source was identified to be an average of 2.7 times more likely than the most likely incorrect source.     

Recommendations for Maintaining a Dermestid Beetle Colony (Dermestes maculatus) for Processing Human Remains

Dermestid beetles (Dermestes maculatus De Geer 1774) are small carrion insects characterized by a rounded or oval-shaped body and white abdomen with black markings. Given their natural propensity to consume soft tissue throughout various stages of decomposition, biological anthropologists have sought to use dermestids as a forensic processing method in addition to traditional chemical tissue removal techniques. Although useful, most of the existing academic literature regarding the upkeep of dermestid colonies for skeletal remains processing either lack specificity or are outdated. Additionally, nonacademic sources that contain information regarding dermestid maintenance are often disjointed, resulting in a difficulty to replicate habitat construction and ideal environmental conditions. Therefore, this technical note presents recommendations for anthropologists interested in establishing and maintaining a D. maculatus population. These recommendations are based on our experiences using several dermestid colonies to process five unembalmed human heads, procured from an anatomical gift company for a larger study on gunshot trauma. Aspects of the dermestids’ environment that are crucial for the management of a healthy colony include the type of bedding, food, water, and containment method used, in addition to maintaining appropriate temperature ranges (24–27°C) and humidity levels (35–73%). Although habitat construction and dermestid maintenance involve materials that are relatively inexpensive and readily available, setting up and maintaining a D. maculatus colony can be laborious and time consuming and should only be undertaken when the volume of casework is such that this investment would be offset.     

Overlooking Feigning Behavior May Result in Potential Harmful Treatment Interventions: Two Case Reports of Undetected Malingering

Clinicians tend to overestimate their ability to recognize feigning behavior in psychiatric patients, especially if it concerns patients who have been admitted for observation. Feigning can be either externally motivated (e.g., for financial compensation, known as malingering) or internally motivated (e.g., to assume the “sick role,” known as factitious disorder). Persistent presentation of severe symptoms is usually associated with the factitious disorder. We present two patients with strong external incentives who consistently and convincingly feigned severe psychiatric symptoms during a protracted period of inpatient observation in a specialized center; both were engaged in a procedure for medical asylum. The first case presented with the clinical picture of a psychotic depression with severe motor symptoms, and the second case showed symptoms of a chronic post-traumatic stress disorder with secondary psychotic symptoms. Both cases were thoroughly investigated but feigning was overlooked, and unnecessary and harmful treatment interventions were given. To prevent iatrogenic damage, we recommend a critical attitude that takes malingering as an option into account in settings where patients are often involved in high stake legal procedures. A clinical sign that might indicate feigning is therapy-resistant symptoms. To rule out feigning a comprehensive, multimethod approach is required, but an active stance toward collateral information is essential. Specialized psychological tests may be useful for preliminary screening, but for their use in culturally diverse populations as in refugee mental health more research is needed.     

Examination of Hacking and Blunt Force Skeletal Trauma

Hacking trauma is prevalent in forensic cases involving genocide and dismemberment, but research into the identification of this type of trauma is lacking. The present study examines characteristics of hacking and blunt force skeletal trauma in order to determine if there is a point at which blunt force trauma becomes distinguishable from hacking trauma. Ten implements with a range of blade angles (i.e., the striking surface of the implement) were used in conjunction with a controlled-force hacking device to impact 100 limb bones of white-tailed deer (Odocoileus virginianus). Observations of the trauma included the occurrence and degree of fragmentation, the entrance widths of the impacts, and composite scores of six hacking characteristics, especially the distinctive V-shaped kerf. ANOVA tests and regression analyses were used to assess the relationships between these characteristics and the blade angles. A significant relationship (p-value = 0.011) was found between the composite hacking scores and the blade angles, indicating that blunt force and hacking trauma can be distinguished. The entrance widths of the impacts exhibited a significant relationship with the blade angles (p-value = 0.037). There was also a significant relationship between the visibility of a V-shaped kerf in the bones (p-value = 0.003), with visibility decreasing around the 60° blade angle. These data should assist in establishing guidelines to differentiate hacking and blunt force skeletal trauma in cases where the implement is on a spectrum between sharp and blunt.     

Evaluating the Potential for Unintentional Occupational Exposure to Fentanyl and Fentanyl Analogues Among Medicolegal Death Investigators and Autopsy Technicians

Recent increases in deaths in the United States from synthetic opioids such as fentanyl and fentanyl analogues (fentanyls) have raised concerns about possible occupational exposures to these potent agents. Medicolegal death investigators and autopsy suite staff might perform job tasks involving exposure to fentanyls. The potential for exposure to fentanyls among medicolegal death investigators and autopsy technicians at a state medical examiner's office was evaluated through review of caseload characteristics, injury and illness logs, and procedures and policies and discussions with management and employee representatives. The evaluation showed that this medical examiner's office had low potential for work-related exposure to fentanyls; its standard operating procedures and personal protective equipment requirements should reduce the potential for occupational exposure. Medicolegal death investigation agencies can develop and implement guidance to control exposures and provide workforce education and training to reduce the potential for work-related exposure to fentanyls.     

Evaluating the Effects of Repeated Psychological Injury: an Introduction to the Special Issue

Psychological Injury and Law -     

Complex Trauma: Missed and Misdiagnosis in Forensic Evaluations

Psychological Injury and Law - Forensic evaluators frequently utilize diagnoses as a way to document the nature and severity of impairment and/or injury in civil and criminal cases despite...     

Parents, Friends, and Romantic Partners: Enmeshment in Deviant Networks and Adolescent Delinquency Involvement

Adolescent networks include parents, friends, and romantic partners, but research on the social learning mechanisms related to delinquency has not typically examined the characteristics of all three domains simultaneously. Analyses draw on data from the Toledo Adolescent Relationships Study (n = 957), and our analytic sample contains 51% male and 49% female as well as 69% white, 24% African-American, and 7% Latino respondents. Parents,’ peers,’ and partners’ deviance are each related to respondents’ delinquency, and affiliation with a greater number of deviant networks is associated with higher self-reported involvement. Analyses that consider enmeshment type indicate that those with both above average romantic partner and friend delinquency report especially high levels of self-reported involvement. In all comparisons, adolescents with deviant romantic partners are more delinquent than those youths with more prosocial partners, regardless of friends’ and parents’ behavior. Findings highlight the importance of capturing the adolescent’s entire network of affiliations, rather than viewing these in isolation, and suggest the need for additional research on romantic partner influences on delinquent behavior and other adolescent outcomes.

Examining Temporal Associations Between School Connectedness and Early Adolescent Adjustment

This study examined (a) the associations between school connectedness and early adolescent adjustment problems over a 1 year period and (b) the equivalence of these associations across gender. Five hundred middle school students (53.4% female), initially in the 6th and 7th grades, participated in the two-wave study. Results from two-group cross-lagged panel analyses were consistent across boys’ and girls’ data. After controlling for baseline levels of adjustment problems, school connectedness predicted lower levels of early adolescent conduct problems 1 year later. Regarding the opposite direction of associations, and even after baseline levels of school connectedness were taken into account, conduct problems predicted lower levels of subsequent school connectedness. There were no cross-lagged associations between depressive symptoms and school connectedness, although elevated levels of baseline depressive symptoms predicted higher levels of subsequent conduct problems. Findings elaborate previous research by demonstrating that early adolescents actively shape the middle school environment.

Physiologic Responses to Racial Rejection Images Among Young Adults from African-American Backgrounds

Physiologic reactivity to racially rejecting images was assessed in 35 young adults (10 males, 25 female) from African-American backgrounds using the startle probe paradigm. In a laboratory setting, participants viewed 16 images depicting racial rejection, racial acceptance, nonracial negative, and nonracial positive themes. While viewing these images, startling bursts of noise were presented and the magnitude of the eyeblink responses were measured. Results supported an attentional mechanism which suggests that, while viewing both racially rejecting and nonracial positive images, individuals may be so absorbed in processing the images that they appear less distracted by the startling noise. However, these patterns were only found for participants low in racial regard. Young adults who felt positively about their racial background did not exhibit differential processing of startle stimuli as a function of slide themes. Race-rejection sensitivity did not moderate startle reactivity. Developmental implications, particularly in light of coping with racial discrimination, are discussed.