International Journal of Offender Therapy and Comparative Criminology

Nearly all information available on sexual homicides are limited to studies conducted in the West. Little is known about sexual homicides that occurred in China. The current study is arguably the first to explore the offender, victim, and offense characteristics of Chinese sexual homicides. Over a period of 23 years (1994 to 2016), the data of 59 cases collected from two data sources (i.e., published Chinese case reports and police data) are examined. Findings indicate that heterosexual assaults are far more prevalent in Chinese sexual homicides. Sexual murderers who averagely aged 32.44 years are mostly males (97%), single (67%), secondary school educated (68%), and with no prior overall (80%) and sexual (88%) convictions. The victims are mostly females (83%) with mean age of 35.35 years. The frequently observed offending patterns include strangers as victim choice (63%), con tactics as victim approach method (57%), sexual pleasure as primary motivation (49%), and personal weapons as murder weapon of choice (41%). Vaginal penetration is a commonly observed sexual assault (88%) and victim body mutilation is also not uncommon (47%). Three case examples are also presented to illustrate the diverse nature and offending patterns of Chinese sexual homicide offenders.

Sexual homicide is a crime of rare occurrence. However, crime severity surveys ranked this form of sexual violence as the second most serious crime. Despite an increase in recent years in the publication of empirical studies on sexual homicide, most of these studies originate from Western countries. Therefore, to our knowledge, no studies to date have tested whether the country where sexual homicides are committed influences the way these crimes are executed by the offenders. The current study attempts to shed additional light on the sexual homicide offender (SHO) by comparing Korean and Canadian SHOs as well as comparing both groups of SHOs with a group of nonsexual homicide offenders (NSHOs). Findings suggest that both Korean and Canadian sexual homicide cases present not only similar patterns but also some specific differences, mainly related to their criminal history, the offender’s age, forensic awareness, and some modus operandi characteristics such as the type of violence and the use of a weapon. Findings are discussed in light of cultural differences between the two countries.

To date, systematic studies of sexual homicides from Europe are scarce, in which none have been conducted in Sweden. This study aims to describe male-on-female sexual homicides in Sweden and differentiate from corresponding nonsexual homicides. Unsolved and solved sexual homicide (n = 33) cases were identified in a database containing all homicides in Sweden between 1990 and 2013 (N = 2,126), and subsequently data from forensic psychiatric evaluations were collected for convicted offenders. Male-on-female sexual homicides constituted 1.6% of all homicides and the clearance rate was 82%, which is comparable with the 83% overall clearance rate but took longer time to solve. Three factors differentiated sexual from nonsexual homicides: strangulation, younger age of the victim, and the absence of eyewitnesses. In solved cases, distance from the offender’s home to the crime scene was strongly correlated with time to clearance. A majority of the offenders suffered from personality disorders, while other diagnoses were uncommon.

The primary objective of this study was to describe and compare the modus operandi, and associated contextual and situational factors, of French serial sexual murderers (SSMs) and nonserial sexual murderers (NSMs). A further objective was to verify the generalizability of the conclusions of James and Proulx’s 2016 systematic review of the modus operandi of sexual murderers, the majority of whom were American or English. Detailed data on the precrime, modus operandi, postcrime, and victimology factors of 120 French sexual murderers (SSMs: n = 33; NSMs: n = 87) were compared. The results suggest that choice-structuring properties that shape the modus operandi of French sexual murderers are similar to those reported by James and Proulx: The modus operandi of French SSMs was shaped by homicidal, sadistic, and rape fantasies, while that of NSMs was shaped by the need to satisfy immediate, especially sexual, needs. However, it should be noted that while the modus operandi of American and English NSMs is primarily shaped by general deviance, that of French NSMs appear be primarily shaped by sexual deviance.

The current study investigates the question of the specificity of sexual homicide offenders by comparing three types of crimes: sexual homicide, nonsexual homicide, and violent sexual assault. The comparison is based on victim, offender and modus operandi characteristics throughout 102 variables. The sample has been taken from a French national police database including 1,736 cases. Among these cases, there are 463 nonsexual homicides, 173 sexual homicides and 1,100 violent sexual assaults. Bivariate and multivariate analyses are performed to highlight the differences. Major differences are observed between, on one hand, sexual homicides and, on the other hand, nonsexual homicides and violent sexual assaults. These differences focus mainly on the offender and modus operandi characteristics. By analyzing specifically the type of observed differences, this research suggests that the sexual murderer and his crime should be analyzed through the lens of a unique type of crime. Findings present implications in terms of correctional practices, offender treatment, and rehabilitation.

Since the 1970s, scholars have produced a large body of research attempting to establish the mechanisms by which sexual serial killers come to arrive at a life of repeat fatal violence. From the standpoint of developmental psychology, however, the explanations offered are far too limited in scope. Human development is the product of complex reciprocal transactions that occur between an individual and their environment throughout their life span. This present study is meant to encourage a critical reconsideration of past knowledge (mainly static traits) in favor of the recognition of the complexity of human development. Using life span developmental psychology as a guiding framework, this study traces the developmental mechanisms that come together to shape the psychopathology that drives the motivations of sexual serial killers.

Sexual child homicides are rare, even among sexual homicides, and no previous study has compared sexual child homicide with nonsexual child homicides. To address this gap in research, this study aims to compare sexual child homicide offenders (n = 8) with two comparison groups: sexual adult homicide offenders (n = 89) and nonsexual child homicide offenders (n = 176) regarding victim, offender, and modus operandi factors. Using bivariate analysis, the results show that although sexual child homicide offenders appear more similar to other sexual homicide offenders than to homicide offenders, sexual offenders targeting children differ from both groups on certain variables. Sexual child homicide offenders more often used strangulation as a method of killing, had intoxicated victims, used multiple locations, and destroyed evidence after the murder. The study concludes that sexual homicide offenders targeting children should be considered distinct from other offenders and that the salient characteristics linked to sadism and instrumentality should be further examined.

The sexual homicide of a child is an unusual event, and very few studies have been conducted on the topic. Previous studies have mainly focused on the differences between sexual homicide of child and adult victims. The current study aims to identify a typology of sexual homicide of children based on modus operandi, offenders’ and victims’ characteristics. Using two-step cluster analysis on a sample of 72 cases of extra familial sexual homicide of children (aged 16 years or below) from France, six clusters have been identified on the basis of eight modus operandi variables: intentional/prepubescent, inadvertent/prepubescent, intentional/preteen, inadvertent/preteen, indiscriminate/teen, and intentional/teen. External validity of the classification was tested using 51 additional variables related to victims, offenders, and other modus operandi characteristics. Findings showed that sexual homicide of children is a heterogeneous phenomenon, largely influenced by the actual age of the victim and the type of violence used. Implications of the findings are discussed considering prevention, criminal investigation, and correctional practices.

Sexual homicide typically implies a crime involving two people: perpetrator and victim. Thus, multiple-perpetrator and multiple concurrent victim sexual murderers are unusual, empirically invisible due to their exclusion from (or burying within) research samples. The present study examines 21 such cases of male sexual murderers having perpetrated at least one sexual homicide either together with a co-offender or alone but killing two victims at once. The aim was to investigate just how unusual, or not, these cases may be in relation to current scientific understanding of sexual murderers and their crimes. A descriptive analysis of offenses (co-offender and offender–victim dynamics, modus operandi) and offender characteristics is presented. Main findings, that multiple-perpetrator and multiple concurrent victim sexual murderers are not so unusual in that they are well conceptualized through application of the established sexualized, grievance, and rape murderer typology, are discussed in relation to clinical and empirical implications.

A nonrandom national sample of 260 sexual homicides (207 nonserial and 53 serial) disclosed 50 cases in which an offender (45 nonserial and 10 serial) inserted a foreign object into a victim’s orifice. The prevalence of foreign object insertion, as well as the types and shapes of inserted objects, where the objects were obtained, the bodily location of insertions, the visibility of inserted objects at the scene, and whether the insertions were pre- or post-mortem are all reported. The foreign object insertion prevalence rate for the sexual homicide sample of cases is 19.2%. Nonserial offenders engaged in foreign object insertion at about the same rate (21.7%) as the serial offenders (18.8%). Our findings do not support the largely held notions—based mainly on case reports—that most offenders who engage in foreign object insertion are psychotic and that the insertion behavior is always post-mortem. The insertion behavior of the nonserial offenders reflects a level of sadism and deviancy comparable with the serial offenders, an unexpected finding with possible prognostic implications.

Sexual sadism and psychopathy are often considered synonymous with sexual homicide, but there is limited research on their associates in sexual homicide offenders. Associates of dimensional measures of sexual sadism (Sexual Sadism Scale; SeSaS) and psychopathy (Psychopathy Check List–Revised [PCL-R] total, Factor 1, and Factor 2) were examined in 51 male Scottish cases. Over a third were DSM-IV (Diagnostic and Statistical Manual of Mental Disorders-IV) sexual sadists, just under a third screened in with the SeSaS, and a quarter were “Hare psychopaths.” Sexual sadism and PCL-R measures were moderately associated. Sexual sadism predicted control, sexual deviance, and unusual behaviour at crime scenes; attempted homicide and having a co-accused; and multiple sexual homicides and previous sexual offending. PCL-R Factor 1 predicted violent, exploitative, and evading detection behaviours at crime scenes; completed homicide; and previous violent offending. PCL-R Factor 2 predicted impulsive behaviours at crime scenes, substance misuse, and previous general offending. Psychopathy and sexual sadism play key roles in sexual homicide, interact with each other, and determine different aspects of offences and offenders.

The Sexual Homicide Crime Scene Rating Scale for Sexual Sadism (SADSEX-SH) is a rating scale which dimensionally measures the degree of offender sexual sadism in suspected sexual homicide cases. Scoring is accomplished using crime scene and related investigative information. Preliminary norms for the SADSEX-SH prototype indicate that it correctly classified offenders with and without sexual sadism. This study further assessed SADSEX-SH sensitivity, specificity, and inter-rater reliability by comparing a larger sample of male sexual homicide offenders with (n = 20) and without (n = 20) sexual sadism. Two items generally undetectable at crime scenes were removed from the originally proposed 10-item scale, resulting in a final 8-item version. SADSEX-SH total scores for the two groups significantly differed (7.7 ± 3.5, range = 2-14 vs. 2.6 ± 2.0, range = 0-7, t = 5.58, p < .001). Inter-rater reliability was excellent (intraclass correlation coefficients [ICCs] = 0.6-1.0). Using a revised cutoff score of 6, sensitivity was 70.0% and specificity was 90%. This revised scale may prove useful for investigators, clinicians, and institutional professionals in helping to identify and address sexual sadism in sexual homicide offenders.

Contrary to popular misconceptions, offenders who kill sex workers as part of their series exhibit substantial variability in their victim selection and behavioral patterns, thus creating additional issues for the investigation of these crimes. This article first aims to outline differences in the demographics of crime scene actions present in homicide series with exclusively sex worker victims and series that includes both sex worker and non–sex worker victims, with the aim of understanding the crime scene aetiology of these two different types of series. Second, the research aims to determine between-series differences of victimology as well as crime scene action between sex worker series and mixed-victim series. Third, the research focuses on mixed-victim series and aims to determine the within-series similarities of victimology and crime scene actions, that is, what factors link sex worker victims and non–sex worker victims in the same series. Data were collected through a large-scale review of international media sources to identify solved serial homicide cases that have included at least one sex worker. Of the 83 series looked at, 44 (53%) included sex worker victims only, and 39 (47%) of the series included both sex worker and non–sex worker victims. The findings highlight the challenges that these types of crime present for investigation and the implications they have on current crime analysis research and practice, and results are discussed in line with theoretical and psychological issues relating to understanding differentiation and similarity, as well as investigative implications relating to linkage blindness and linking of serial crimes.

Sex workers as a group are one of the more common targets in serial homicide, yet the most likely to go unsolved. Part of the reason for this is the difficulty in linking individual crime scenes to a series, especially in those series where offenders not only target sex worker victims but also target non-sex worker victims. Inconsistencies in both victim targeting and behaviors engaged in across series add to the difficulties of linking and solvability in these types of crimes. The current study aimed to add to the current body of literature on serial crime linkage by examining not only the most salient behavioral indicators useful for crime scene classification of serial homicides that involve sex worker victims but also examine the trajectories of behavioral change that can help link apparently inconsistent crime scenes and proposes the new Model for the Analysis of Trajectories and Consistency in Homicide (MATCH). The study examines 83 homicide series, including 44 (53%) series where all victims were sex workers and 39 (47%) series that included a mix of sex workers and non-sex worker victims. Using the MATCH system allowed for the majority of series to be classified to a dominant trajectory pattern, over half as many as a traditional consistency analysis that focusses on behavioral similarity matching. Results further showed that Sex Worker Victim series were almost three times more consistent across their series than Mixed-Victim series, not only in victim selection but also in the overall behavioral patterns. Findings are discussed in line with theoretical and psychological issues relating to understanding the nature of behavioral consistency and the importance of going beyond simple matching toward a model that allows for the identification of consistency in seemingly inconsistent series, as well as investigative implications relating to linking serial crimes.

The study investigated whether different types of sexual homicide perpetrators are more or less skilled at delaying detection. A newly proposed direct/indirect typology was used alongside information about the time of arrest, the frequency of specific precautions as well as the impact of forensic strategies used by the perpetrators to examine skill at delaying detection. The results indicated that the time from the killing to the arrest, as measured in days, was longer for the direct than the indirect sexual killers. Despite the fact that the direct aggressors were better at delaying detection, overall the indirect and the direct offenders did not differ in the frequency of use of most of the precautions. However, different forensic awareness strategies were more efficacious for the direct and the indirect offenders. These results are discussed in relation to the crime scripts for the two perpetrator groups.