Trisomy 21 disclosure using STR and SNP markers typed by MiSeq FGx™ Forensic Genomics System

The presence of a tri-allelic pattern at a single locus in a multiplex short tandem repeat (STR) profile is a rarely observable event. Generally, based on peak height measured by the capillary electrophoresis (CE) method and combination of alleles, the tri-allelic pattern is distinguishable into two predominant types: type 1 and 2, which are caused, respectively, by somatic mutations and chromosomal rearrangements. When tri-allelic patterns at more than one STR located on the same chromosome are detected, there is a reasonable suspicion of a trisomy due to an extra copy of a chromosome. Therefore, information on the type of three-band pattern is usually limited to STRs localized on the same chromosome included in the forensic kit in use and sometimes in insufficient numbers to classify this event correctly. The opportunity to extend this evaluation to additional markers, such as SNPs detectable using NGS, has not yet been explored. In this study, using the ForenSeq™ DNA Signature Prep kit, two cases of autosomal aneuploidy were revealed on chromosome 21, relying not only on STRs assessment but also extending the analysis to the five identity-informative single nucleotide polymorphisms (iiSNPs) localized on chromosome 21.     

VARIETIES OF VIOLENT BEHAVIOR

There is an implicit assumption of homogeneity across violent behaviors and offenders in the criminology literature. Arguing against this assumption, I draw on three distinct literatures [child abuse and neglect (CAN) and violence, violence and post‐traumatic stress disorder (PTSD), and CAN and PTSD] to provide a rationale for an examination of varieties of violent behaviors. I use data from my prospective cohort design study of the long‐term consequences of CAN to define three varieties of violent offenders using age of documented cases of CAN, onset of PTSD, and first violent arrest in a temporally correct manner [CAN → to violence, CAN → PTSD → violence (PTSD first), and CAN → violence → PTSD (violence first)], and a fourth variety, violence only. The results illustrate meaningful heterogeneity in violent behavior and different developmental patterns and characteristics. There are three major implications: First, programs and policies that target violence need to recognize the heterogeneity and move away from a “one‐size‐fits‐all” approach. Second, violence prevention policies and programs that target abused and neglected children are warranted, given the prominent role of CAN in the backgrounds of these violent offenders. Third, criminologists and others interested in violence need to attend to the role of PTSD, which is present in about one fifth (21 percent) of these violent offenders, and not relegate the study of these offenders to the psychiatric and psychological literatures.     

Testing moffitt's neuropsychological variation hypothesis for the prediction of life-course persistent offending

Abstract

Although neuropsychological deficits have been linked to antisocial behavior, theories of crime have been slow to develop formal processes and predictions for neuropsychological deficits. One recently articulated theory, however, places emphasis on the influence of neuropsychological variation in the development of antisocial behavior. In her developmental taxonomy. Moffitt outlines a theory of antisocial behavior that rests on the presence of two groups of offenders: life-course persisters and adolescent-limiteds. Both groups occupy distinct etiologies for antisocial involvement and are believed to engage in different antisocial activities. One of the main differences between the two groups is the role that neuropsychological deficits play in the production of antisocial behavior. Moffitt hypothesizes that neuropsychological deficits are predictive of antisocial involvement for life-course persisters but not for adolescent-limiteds. Using data from the Philadelphia portion of the National Collaborative Perinatal Project, proxy measures of neuropsychological deficits are used to predict four different manifestations of life-course persistent offending. Results support Moffitt's hypothesis about the relationship between poor neuropsychological test scores and life-course persistent styles of offending.     

The effects of marital breakdown on offending: results from a prospective longitudinal survey of males

Abstract

We examined the factors that predicted marital separation in the Cambridge Study in Delinquent Development, which is a prospective longitudinal survey of 411 London males. We found that dishonesty, having a wife with a conviction(s), convictions, a poor relationship with parents, no exams passed, unprotected sex and having a shotgun marriage predicted marital breakdown. Males from broken homes due to marital conflict had a moderate risk of suffering marital breakdown themselves but the effect was mediated by having conviction(s). An analysis in which separated men were matched with controls on age at marriage, prior convictions and a propensity score predicting the likelihood of separation showed that a man's convictions increased after becoming separated. However, if a man formed a new intimate relationship, the increase in convictions after separation was reduced.     

Testing the impact of group offending on behavioural similarity in serial robbery

Behavioural case linkage assumes that offenders behave in a similar way across their crimes. However, group offending could impact on behavioural similarity. This study uses robbery data from two police forces to test this by comparing the behavioural similarity of pairs of lone offences (LL), pairs of group offences (GG) and pairs of offences where one crime was committed alone and the other in a group (GL). Behavioural similarity was measured using Jaccard's coefficients. Kruskal–Wallis tests were used to examine differences between the three categories within the linked samples. No statistically significant differences were found for linked GG compared to linked LL pairs. However, differences emerged between GL and the other categories for some behaviours (especially control) suggesting caution should be applied when linking group and lone offences committed by the same perpetrator. Differences between linked and unlinked pairs were assessed using receiver operating characteristic. The results suggest it is possible to distinguish between linked and unlinked pairs based on behaviour especially within the GG and LL categories. There were, however, fewer significant findings for the GL sample, suggesting there may be issues linking crimes where the offender commits one crime as part of a group and the other alone.     

Predicting multiple victim versus single victim sexual abuse: an examination of distal factors and proximal factors associated with the first abuse incident

Abstract

Official and confidential self-report data on 83 convicted adult male sexual abusers were analysed to examine whether sexual offending progression can be better predicted from distal antecedents, or from proximal antecedents and outcomes associated with the first sexual abuse incident. Fifty-six offenders who sexually abused more than one victim (multiple victim offenders; MVOs) were compared to 27 offenders who sexually abused a single victim only (single victim offenders; SVOs). MVOs were younger at the time of their first sexual abuse incident, and were more likely to first abuse male and non-familial children. With the exception of sexual attraction to male children, no differences were found between the two groups on distal antecedents. Proximal antecedents and outcomes associated with the first sexual abuse incident were significantly related to multiple victim offending. Logistic regression analysis identified the presence of sexual difficulties in the month prior to the first abuse incident, and sexual excitement immediately preceding the first incident, as significant unique predictors. Implications for risk assessment and risk management are discussed, and future research directions proposed.     

Understanding sexual homicide

Abstract

Sexual homicide is a crime that receives much media attention, but one that still has a relatively small research base compared to other crimes. Although the idea of someone deriving sexual gratification from or during the killing of another is an anathema to many, forensic professionals need to understand sexual homicide and the range of circumstances and motivations that lie behind it. This paper explores this complex crime: it illustrates the various definitions and labels used; it suggests that sexual homicide is rare and is committed by individuals who, although having troubled histories, may not differ from other offenders. Then, by examining the various legal and behavioural circumstances in which sexual homicide can occur, this paper illustrates the diversity of sexual homicide and presents it in a more understandable manner. Finally, the paper suggests that knowledge of this diversity is required both for investigative and clinical purposes.     

Performance intelligence,sexual offending and psychopathy

Abstract

Previous studies have suggested that offenders have lowered verbal intelligence compared to their performance intelligence. This phenomenon has been linked traditionally to childhood risk factors (e.g. deficient education, abuse and neglect). Substantial discrepancies between performance intelligence quotients (PIQ) and verbal intelligence quotients (VIQ), however, might also point to neurobiological impairments which may be associated with specific types of criminal behaviour. From the files of 133 male hospitalized offenders, PIQ, VIQ, full scale IQ (FSIQ) scores and Psychopathy Checklist–Revised (PCL-R) scores were derived, along with information about their criminal histories. PIQ over VIQ discrepancies were most pronounced in sexual offenders, particularly in those who had committed sexual crimes against adult victims. Furthermore, PIQ as well as PIQ higher than VIQ discrepancies correlated modestly, but significantly, with PCL-R scores. The results suggest that lower verbal compared to visual and spatial abilities may be connected specifically to egocentric and narcissistic personality traits which, in turn, may be involved in raising the risk of sexual offending.     

Application of the clinical polygraph examination to the assessment,treatment and monitoring of sex offenders

Abstract

Post Conviction Clinical Polygraph Examination Testing (Lie Detector Testing) offers significant opportunities for assessing, treating and monitoring sex offenders. This article briefly reviews the historical development of polygraph techniques including the physiological measures employed, the administration of the polygraph and the interpretation of data collected. Criticisms of polygraphy are explored and information concerning the scientific acceptability of these procedures is given. The current influence of polygraphy in sex offender work is reviewed. Evidence is given of the utility of polygraphy in reducing denial, improving treatment outcomes and more effectively supervising sex offenders on probation or license. Cost benefit considerations are examined, as well as the need for further controlled research and future regulation of the polygraph, if it is to be introduced in Britain. Planned UK Trials are described.