Decision making and examiner bias in forensic expert recommendations for not guilty by reason of insanity

Source of nomination (prosecution, defense, judge) was varied in a fictional not guilty by reason of insanity (NGRI) case distributed to 180 community forensic evaluators in a state employing theM'Naghten rule. Differences among examiners by appointment for the final NGRI judgment was not significant; interrater reliability for psychopathological symptomatology was .73. Discriminant analysis revealed significant differences in the decision-making process between evaluators recommending sanity and those endorsing insanity, as well as between psychiatrists and psychologists.     

Atomic force microscopy as a biophysical tool for nanoscale forensic investigations

The atomic force microscope (AFM) has found its way to the arsenal of tools available to the forensic practitioner for the analysis of samples at the nano and microscales. As a non-destructive probing tool that requires minimal sample preparation, the AFM is very attractive, particularly in the case of minimal or precious sample. To date, the use of the AFM has primarily been in the arena of imaging where it has been complementary to other microscopic examination tools. Forensic applications in the visual examination of evidence such as blood stains, questioned documents, and hair samples have been reported. While a number of reviews have focused on the use of AFM as an imaging tool for forensic analyses, here we not only discuss these works, but also point to a versatile enhancement in the capabilities of this nanoscale tool – namely its use for force spectroscopy. In this mode, the AFM can determine elastic moduli, adhesion forces, energy dissipation, and the interaction forces between cognate ligands, that can be spatially mapped to provide a unique spatial visualization of properties. Our goals in this review are to provide a context for this capability of the AFM, explain its workings, cover some exemplary works pertaining to forensic sciences, and present a critical analysis on the advantages and disadvantages of this modality. Equipped with this high-resolution tool, imaging and biophysical analysis by the AFM can provide a unique complement to other tools available to the researcher for the analysis and characterization of forensic evidence.     

Child murder committed by severely mentally III mothers: an examination of mothers found not guilty by reason of insanity. 2005 Honorable Mention/Richard Rosner Award for the best paper by a fellow in forensic psychiatry or forensic psychology

Forensic hospital records of 39 severely mentally ill mothers adjudicated Not Guilty by Reason of Insanity for filicide (child murder by parents) were analyzed to describe characteristics preceding this tragedy and to suggest prevention strategies. Almost three-quarters of the mothers (72%) had previous mental health treatment. Over two thirds (69%) of the mothers were experiencing auditory hallucinations, most frequently command hallucinations, and half (49%) were depressed at the time of the offense. Over one third (38%) of the filicides occurred during pregnancy or the postpartum period, and many had a history of postpartum psychosis. Almost three-quarters (72%) of the mothers had experienced considerable developmental stressors, such as death of their own mother or incest. Maternal motives for filicide were predominantly "altruistic" (meaning murder out of love) or "acutely psychotic" (occurring in the throes of psychosis, without rational motive). Psychiatrists should perform careful risk assessments for filicide in mothers with mental illnesses.     

Thermogravimetric analysis as a polymer identification technique in forensic applications

This paper investigates the potential of thermogravimetric analysis (TGA) as a tool for determination of different species of polymers. Materials analyzed include polyvinyl chloride (PVC), chlorinated polyvinyl chloride (CPVC), polystyrene, polypropylene, nitriles, and nylon. Analyses showed excellent discriminating results even when samples were contaminated with silicates, organics, moisture, and char. The techniques developed were designed with a forensic-type analysis in mind, such as analysis of blast fragments and arson debris. Techniques were developed that gave satisfactory results even when sample sizes were less than five milligrams.     

Hair as a source of forensic evidence in murder investigations

Obtaining palynological and other botanical evidence from murder victims is becoming part of routine mortuary protocol in the United Kingdom. Forensic pathologists are often keen to cooperate in the collection of classes of material that have, in the past, been considered to be of little importance in criminal investigation. Work over the last eight years has demonstrated the great value in scrutinising cadavers for the presence of plant material and/or soil stains. Macroscopic plant remains and palynomorphs (pollen, spores and other microscopic entities) retrieved from skin and hair have allowed the differentiation of murder scenes from places of eventual deposition. Furthermore, although the opportunity has not yet presented itself, obtaining palynological evidence from the hair of suspects is feasible. During an offence, the offender might have had physical contact with foliage or the ground. Pollen and spore assemblages picked up by hair during that activity might provide forensic evidence for contact. Brief details of some aspects of case histories are presented to demonstrate the value of sampling cadavers. One case has been through the courts while the other is ongoing and, therefore, cannot be identified.     

Age-related changes in pulp cavity of incisors as a determinant for forensic age identification

To find a simple and convenient method for age identification upon age-related pulp cavity narrowing, the mesiodistal diameters of the cervical pulp chamber, the middle and terminal parts of the root canal of the pulp cavity of 620 incisors were measured on radiographs taken in situ in 80 Chinese aged from 15 to 80. It was shown that the three mesiodistal diameters significantly decreased in a negative linear relationship with age (-0.4233 ≤ r ≥ -0.8465) in all incisors, but the narrowing velocity of the cervical pulp chamber and the middle part of the root canal in the maxillary incisors (b = -0.02 mm) was faster than that in the mandibular incisors (b = -0.01 mm). Accordingly, a mathematical model describing the ages as a function of any one of the three mesiodistal diameters of the pulp cavity was deduced, which would be useful for age identification in forensic medicine or archaeology.     

Evaluation of gastrointestinal cancer tissues as a source of genetic information for forensic investigations by using STRs

Malignant tissue samples may sometimes be the only source of biological material for forensic investigations, including identification of individuals or paternity testing. However, in use of such samples, uncertainties due to microsatellite instability (MSI) and loss of heterozygosity (LOH) often associated with neoplasias may be encountered. In this study, we have analysed the applicability of autosomal tetranucleotide short tandem repeat (STR) markers, which are routinely used in forensic analysis, to gain genetic information. MSI and LOH were analysed in 41 surgically removed gastrointestinal cancer specimens and the adjascent non-cancerous tissue marginals. The cancer specimens showed great variability in their genetic phenotypes due to MSI or LOH, with only 32% being microsatellite-stable. Of the 15 autosomal STR loci analysed, only TH01 had no MSI-type alteration in these samples. The loci most frequently affected by MSI were D8S1179, D21S11, D18S51 and D19S433 (MSI in 15-17% of cases). LOH-type alterations were observed at all of the loci, including the amelogenin locus used for sex determination. The highest LOH frequency was found at locus D18S51 (27%). The genetic alterations at the marker loci may indicate false homozygosity or heterozygosity, and false gender may result from erroneous deduction of DNA profiles. Therefore, typing of autosomal STRs from malignant tissues in forensic settings warrants careful interpretation of MSI and LOH results together with microscopic analysis of a tissue specimen. Results by two commercially available and widely used forensic DNA profiling kits used here were comparable.     

Mindful yoga as an adjunct treatment for forensic inpatients: a preliminary evaluation

Although emerging evidence of yoga interventions shows benefits for people with schizophrenia, research is lacking regarding yoga interventions among forensic inpatients. This pilot study investigated the acceptability and effectiveness of an eight-week mindful yoga programme in improving psychological outcomes in 26 forensic inpatients. Outcome measures included the Five Facet Mindfulness Questionnaire, the Perceived Stress Scale, the Hospital Anxiety and Depression Scale and the Clinical Outcomes in Routine Evaluation – Outcome Measure as well as a qualitative component post-intervention and at two-month follow-up. Trends in the predicted direction suggested reductions in clinical symptoms over time, specifically anxiety. Key themes revealed increased body awareness, relaxation and self-directed yoga practices and breathing techniques for anxiety management. Ninety-two percent reported acceptance of the programme. Preliminary findings are encouraging and warrant further research into the application of mindful yoga in the management of distress and risk with forensic inpatients.     

DNA barcoding as a tool for species identification in three forensic wildlife cases in South Africa

Poaching of wildlife animals for subsistence and commercial purposes has lead to population declines in Africa. In forensic cases, a need exists to identify the species of origin of carcasses, meat or blood. In the study presented here, the mitochondrial COI gene was sequenced to determine the species of unknown samples in three suspect South African forensic wildlife cases. In two cases the unknown samples were identified as originating from domestic cattle (Bos taurus) and in the third case the sample was identified as common reedbuck (Redunca arundinum). This is the first report of the COI sequence of common reedbuck. The study highlights the need for accurate wildlife reference material from each country in order to convict wildlife cases.     

Immunohistochemical staining as a potential method for the identification of vaginal epithelial cells in forensic casework

There is currently no accurate method to identify vaginal epithelial cells uniquely. This study aimed to use a cell extraction procedure compatible with routine forensic sampling methods, and to investigate the expression of cytokeratin (CK), estrogen receptor-alpha (ERalpha), and phosphodiesterase 5 (PDE5) in order to distinguish between skin, buccal, vaginal, and external penile epithelial cells. Seminal fluid samples were also examined. Epithelial cell samples were fixed in formalin, embedded in agarose, and processed using histological methods. Antigen-antibody reactions were detected using the DAKO Envision+ detection system. CK was present in all cells from all five sources confirming the origin of cells as epithelial. Both ERalpha and PDE5 positively labeled vaginal, buccal, and skin epithelial cells. Although an antigen unique to vaginal epithelial cells was not identified, we have described a cell extraction procedure for use in the immunohistochemical detection of a wide range of antigens, an approach compatible with forensic diagnostics.     

Learning in practice for becoming a professional forensic expert

The study explores the professional development of future forensic experts. Specifically, it investigates how the forensic expert trainees learn through the internal training program at the Swedish National Laboratory of Forensic Science with a focus on the supervision at work. The findings are drawn from an ethnographical study where five trainees and their supervisors have been observed and interviewed. By drawing on a socio cultural perspective on learning, the results show that supervision is crucial for professional development. Two types of activities and relations define how supervision is implemented. There is a "transitional movement" in how supervision is staged depending on the trainees' gradual changes in participation in the work practice and increased experience. Forensic experts need skills and know-how to make wise and impartial judgments, i.e. a kind of tacit professional practical knowledge, as well as the skill to communicate with other professionals. However, the development of a professional language is somewhat unspoken or planned. Becoming a forensic expert is a learning process in practice where supervision plays a decisive role in maintaining the professional knowledge in the judicial system. Therefore, supervision for supervising might be a valuable support for supervisors.     

HCR-20 violence risk assessments as a guide for treating and managing violence risk in a forensic psychiatric setting

Abstract

Over the past decades there has been a vast development in the research into risk factors for violence and the development of risk assessment instruments. One instrument that has been given special attention is the HCR-20 violence risk assessment scheme. However, little attention has been paid to the clinical applicability of this tool, i.e. how does this assessment scheme perform when utilized in clinical practice as a tool to guide intervention and management in order to alleviate risk of violent behaviour? The present study was a true prospective study into the utilization of the HCR-20 as a clinical routine. Data on forensic psychiatric patients (n = 81) from a forensic unit in Denmark are presented. As part of a clinical routine all patients were assessed for risk of future violence utilizing the structured professional judgement model, the HCR-20. Outcome measures were aggressive episodes during hospitalization and new convictions post discharge. The predictive validity of the HCR-20 was lower compared with previous findings. It is argued that this does not necessarily indicate poor predictive accuracy of the HCR-20. Rather, it may indicate that the HCR-20 is suitable for guiding risk management in order to prevent violent behaviour.     

Teeth as a source of DNA for forensic identification of human remains: A Review

Teeth and bones are frequently the only sources of DNA available for identification of degraded or fragmented human remains. The unique composition of teeth and their location in the jawbone provide additional protection to DNA compared to bones making them a preferred source of DNA in many cases. Despite this, post-mortem changes in the structure and composition of teeth, and the location and diagenesis of DNA within them are poorly understood. This review summarises current knowledge of tooth morphology with respect to DNA content and preservation, and discusses the way in which post-mortem changes will affect the recovery of DNA from teeth under a range of commonly used extraction protocols. We highlight the benefits and pitfalls of using specific tooth tissues for DNA extraction and make recommendations for tooth selection and sampling that will maximise DNA typing success. A comprehensive understanding of tooth structure and an appreciation of the relationship between DNA and mineralized tissues in post-mortem teeth are critical for optimal sample selection. More informed sampling methods that target specific tooth tissues will increase the likelihood of successful genetic analysis and allow for efficient and timely missing persons case work and disaster victim identification response.     

Pressing need for national governmental recognition of forensic anthropology in South Africa as illustrated in a medico-legal case

Forensic anthropology in South Africa is well developed in the higher education sector, with advanced training and research programmes. Despite this and decades of academic involvement in casework, forensic anthropology still lacks a defined framework and mandate at a governmental level. Therefore, the involvement of forensic anthropologists’ expertise varies markedly between cases, provinces, and among various stakeholders within the country, to the detriment of dispensation of social and criminal justice. The lack of clearly defined guidelines for the rendering of the service was exemplified and demonstrated through a recent forensic case. Here, contextual information was absent, and the remains posed a challenge to analyse, ostensibly due to missing information. Numerous questions were raised during the analysis of the remains, and broader concerns about the investigative involvement of a forensic anthropologist within South African casework were brought to the fore. Through the analysis of this case, we describe the deductive processes that led to the formation of an opinion that the skeletal linear defects were the result of taphonomic changes. In addition, we highlight how these efforts where constrained and each step in the process unnecessarily hindered. Finally, we demonstrate the capacity and willingness of forensic anthropology practitioners to be involved, and how, without governmental support, it is a great potential lamentably untapped.     

Naturalistic decision making in forensic science: toward a better understanding of decision making by forensic team leaders

This study uses the naturalistic decision-making (NDM) perspective to examine how Dutch forensic team leaders (i.e., the officers in charge of criminal forensic research from the crime scene until the use of laboratory assistance) make decisions in real-life settings and identifies the contextual factors that might influence those decisions. First, a focus group interview was conducted to identify four NDM mechanisms in day-to-day forensic decision making. Second, a serious game was conducted to examine the influence of three of these contextual mechanisms. The results uncovered that forensic team leaders (i) were attracted to obtain further information when more information was initially made available, (ii) were likely to devote more attention to emotionally charged cases, and (iii) used not only forensic evidence in the decision making but also tactical, unverified information of the police inquiry. Interestingly, the measured contextual influences did not deviate significantly from a control group of laypeople.