Testing the Assumption of Behavioural Consistency in a New Zealand Sample of Serial Rapists

<p>One of the assumptions that underlies the profiling process is that criminals are behaviourally consistent from one offence to another. To date, however, this is an assumption that has not been scientifically validated. The present study therefore tested the assumption of behavioural consistency in serial rape offences. The author collected dichotomous data on 30 behavioural variables for a total of 439 offences committed by 121 serial rapists in New Zealand. There were two main research aims of the study. The first aim was to test the behavioural consistency of a range of individual behaviours. It was hypothesised that higher consistency would be found for behaviours that reflected a degree of planning or that prioritised control of the victim and the offence environment, because these behaviours might be less affected by environmental factors. In contrast, many sexual behaviours arise directly out of offender-victim interactions and therefore are most affected by environmental factors such as victim resistance. It was therefore also hypothesised that sexual behaviours would display lower consistency. A consistency measure was used that compared behaviour in consecutive offences. Consistency for each behaviour was defined as present-present or absent-absent matches of that behaviour in consecutive offences. The degree of consistency for any behaviour will be reflected in the consistency score received by that variable based on the number of matches for that behaviour across the offence series. The consistency analysis found moderate to high levels of consistency for the majority of individual behaviours. As predicted, higher consistency was exhibited for behaviours that prioritised control of the victim and the offence environment, and lower consistency was exhibited for the sexual behaviours. The second research aim was that if behavioural consistency was found in the results of the consistency analysis, to explore whether there were any underlying patterns to the consistency of offending behaviour. A factor analysis of the consistency scores established that there are clear patterns to the behavioural consistency of offenders consistent with previous analysis of offence characteristics. The factor analysis resulted in three themes or domains to behaviour: hostility, involvement and control. These findings have theoretical implications for the assumption of behavioural consistency in serial rapists, for the concepts of modus operandi and signature in offence behaviour, and for the theoretical understanding of the profiling process. The findings also have practical implications for the practice of profiling and case linkage in New Zealand, and raise possibilities for future directions in research.</p>

Testing the Assumption of Behavioural Consistency in a New Zealand Sample of Serial Rapists

<p>One of the assumptions that underlies the profiling process is that criminals are behaviourally consistent from one offence to another. To date, however, this is an assumption that has not been scientifically validated. The present study therefore tested the assumption of behavioural consistency in serial rape offences. The author collected dichotomous data on 30 behavioural variables for a total of 439 offences committed by 121 serial rapists in New Zealand. There were two main research aims of the study. The first aim was to test the behavioural consistency of a range of individual behaviours. It was hypothesised that higher consistency would be found for behaviours that reflected a degree of planning or that prioritised control of the victim and the offence environment, because these behaviours might be less affected by environmental factors. In contrast, many sexual behaviours arise directly out of offender-victim interactions and therefore are most affected by environmental factors such as victim resistance. It was therefore also hypothesised that sexual behaviours would display lower consistency. A consistency measure was used that compared behaviour in consecutive offences. Consistency for each behaviour was defined as present-present or absent-absent matches of that behaviour in consecutive offences. The degree of consistency for any behaviour will be reflected in the consistency score received by that variable based on the number of matches for that behaviour across the offence series. The consistency analysis found moderate to high levels of consistency for the majority of individual behaviours. As predicted, higher consistency was exhibited for behaviours that prioritised control of the victim and the offence environment, and lower consistency was exhibited for the sexual behaviours. The second research aim was that if behavioural consistency was found in the results of the consistency analysis, to explore whether there were any underlying patterns to the consistency of offending behaviour. A factor analysis of the consistency scores established that there are clear patterns to the behavioural consistency of offenders consistent with previous analysis of offence characteristics. The factor analysis resulted in three themes or domains to behaviour: hostility, involvement and control. These findings have theoretical implications for the assumption of behavioural consistency in serial rapists, for the concepts of modus operandi and signature in offence behaviour, and for the theoretical understanding of the profiling process. The findings also have practical implications for the practice of profiling and case linkage in New Zealand, and raise possibilities for future directions in research.</p>

Predicting rapist type based on crime-scene violence, interpersonal involvement, and criminal sophistication in U.S. stranger rape cases

Stranger rape cases are one of the most difficult sexual assault crimes to solve for law enforcement. This study aimed to compare crime-scene characteristics between serial rapists and single-victim rapists in stranger rape cases and build a predictive model to predict rapist type. An archival database of released sex offenders included 385 who committed stranger rapes. Of those, 244 were single-victim rapists and 141 were serial rapists. The single-victim rapists were significantly more likely to have violently themed crime-scene characteristics than serial rapists, whereas serial rapists were significantly more likely than single-victim rapists to engage in criminally sophisticated behavior and induce participation from their victims. A logistic regression using 10 crime-scene characteristics correctly identified 75.8% of cases as perpetrated by either single-victim or serial rapists. The most significant predictors of rapist type were whether the offender digitally penetrated their victim, whether the offender choked their victim, whether they were at a new/unknown location or whether they threatened their victim. The implications of these results are that they benefit law enforcement in the investigation of stranger rape cases by potentially narrowing down their suspect pool and add to the classification of stranger rapists in offender profiling literature.

Perfil de los violadores seriales: un análisis de casos

La presente investigación comprende un estudio empírico sobre los violadores seriales, en el que se tiene en cuenta el análisis de diversos sucesos ocurridos en España, a partir de diferentes sentencias judiciales. El objetivo de este trabajo radica en la creación de un perfil criminal, comparando diferentes variables que nos permiten obtener características comunes a esta tipología delictiva.The present research includes an empirical study of serial rapists, taking in to account the analysis of several events that occurred in Spain, based on judicial sentences. This work goals to create a criminal profile, comparing different variables allowing us to obtain characteristics, which are common to this criminal typology.

Serial Rapists and Wrongful Conviction

This chapter describes a common pattern where innocent defendants are tried and convicted of crimes committed by serial rapists. These cases account for a significant portion not only of the wrongful convictions in sexual assaults, but also of all confirmed wrongful convictions. The chapter presents 67 defendants wrongfully convicted with this set of case facts. This chapter identifies the difficulty encountered by law enforcement in the investigation of “stranger rapes” despite the expanding literature on crime scene investigation and offender profiling. This chapter also highlights the law enforcement focus on ruling out false rape charges, while less attention is paid to the matter of unreliable identification.

Pharmacological treatment of sex offenders

Most people recognize that incarceration alone will not solve sexual violence. Indeed, treating the offenders is critical in an approach to preventing sexual violence and reducing victimization. In most cases, a diagnosis of paraphilia is associated with sexual violence. This review is intended to present and summarize the first recently published international guidelines about pharmacological treatment of paraphilias. Pharmacological interventions should be part of a more comprehensive treatment plan including psychotherapy and, in most cases, behavior therapy. Antiandrogens, and mostly GnRH analogues, significantly reduce the intensity and frequency of deviant sexual arousal and behavior. GnRH analogue treatment constitutes the most promising treatment for sex offenders at high risk of sexual violence, such as pedophiles or serial rapists, however informed consent is necessary. SSRIs remain an interesting option in adolescents, in patients with depressive or OCD disorders, or in mild paraphilias such as exhibitionism.Disclosure of interestThe author has not supplied his declaration of competing interest.

The National Problem of Untested Sexual Assault Kits (SAKs): Scope, Causes, and Future Directions for Research, Policy, and Practice

Victims of sexual assault are often advised to have a medical forensic exam and sexual assault kit (SAK; also termed a “rape kit”) to preserve physical evidence (e.g., semen, blood, and/or saliva samples) to aid in the investigation and prosecution of the crime. Law enforcement are tasked with submitting the rape kit to a forensic laboratory for DNA (deoxyribonucleic acid) analysis, which can be instrumental in identifying offenders in previously unsolved crimes, confirming identify in known-offender assaults, discovering serial rapists, and exonerating individuals wrongly accused. However, a growing number of media stories, investigative advocacy projects, and social science studies indicate that police are not routinely submitting SAKs for forensic testing, and instead rape kits are placed in evidence storage, sometimes for decades. This review article examines the growing national problem of untested rape kits by summarizing current research on the number of untested SAKs in the United States and exploring the underlying reasons why police do not submit this evidence for DNA testing. Recommendations for future research that can guide policy and practice are discussed.