Sadism among sexual homicide offenders:Validation of the Sexual Sadism Scale

Sexual sadism is assumed to be a crucial factor in sexual homicide. Prevalence estimates vary greatly due to differences in the definition of sexual sadism. A nationwide sample of 350 male perpetrators who had committed a sexual homicide offense against a female 14 years of age or above in England or Wales was assessed based on archival records. Sexual sadism was assessed using the Sexual Sadism Scale (SeSaS). Item response theory (IRT) analyses were conducted focusing on the 2-parameter logistic model. The single-factor structure of the SeSaS Part 1 was tested using confirmatory factor analysis. Estimates of both internal consistency and interrater agreement were satisfactory to substantial. IRT analysis showed that the Part 1 items captured moderate to severe levels of the latent construct (i.e., theta levels >0). Based on the Posterior Probability of Diagnosis index, the prevalence of the disorder was estimated at 37% in the sample. The substantial correlation between the SeSaS Part 1 total score and original clinical diagnoses of sadism confirms the criterion validity of the scale. Exertion of control and infliction of torture were among the more informative items. In sum, the results support the usefulness of the SeSaS instrument for assessing forensically relevant forms of sadism

After a storm comes a calm: International expert decision-making process regarding abstract definitions of emotional cool-off periods in sexual homicide

The Federal Bureau of Investigation coined the term ‘emotional cool-off period’ in relation to serial homicide defining it as any amount of time between kills where the perpetrator returns to their everyday life (Douglas et al., 1986). Since the term’s conception, cool-off periods have become a fundamental aspect of defining serial versus non-serial homicide cases in academia. Despite its usage frequency, it has been neither firmly defined nor empirically investigated. The present study aims to investigate the specific underpinnings of emotional cool-off periods in sexual homicide by utilising experts’ opinion in relation to distinguishing between serial and non-serial homicide cases. Twenty-eight experts took part in the study and they each scored 10 sexual homicide scenarios for emotional cool-off presence as well as influential factors they relied on when making their decision. The results indicated that inter-rater agreement was ‘poor’ across experts. When experts believed an emotional cool-off period was present, they relied on cognitive state indicators whereas when they believed an emotional cool-off period was absent they relied on evidence of arousal. The time was second most frequent factor. This suggests that experts prefer to base their judgement on the presence (rather than absence) of forensic evidence available to them

The developmental and criminal histories of subgroups of sexual murderers engaging, or not engaging, in post mortem sexual interference, compared to rapists

Purpose Identifying factors that may predict sexual aggression in the context of directly sexual murder, indirectly sexual murder, and non-fatal outcomes is necessary for advancing a field lacking a substantiated multifactorial theoretical model. Methods Eighty-nine sexual murderers engaging in post mortem sexual interference were compared to 92 non-post mortem sexual interference sexual murderers and 72 rapists on developmental factors, adult lifestyle, and criminal history. An overall model was built using a series of multinomial logistic regression analyses. Results Unlike rapists, both groups of sexual murderers experienced a lack of success in sexually intimate relationships. Perpetrators of post mortem sexual interference were rarely necrophiles, but having a history of sadistic behaviors or interests uniquely predicted sexual murder involving post mortem sexual interference. Chronic violent and sexual offending was characteristic of rapists. Psychopathy, measured using the screening version of the Psychopathy Checklist (Hart, Cox, & Hare, 1995), was not predictive of any outcome. Conclusion Results support criticism of existing theoretical models; that they do not apply to non-sadistic sexual murder. Findings are discussed in relation to gaps in theoretical understanding of sexual murder, and concerning implications for forensic policies and practice

Unveiling the Shadows: Investigating the Interplay of Stalking and Sexual Homicide – A Case Study

Stalking can be defined as a pattern of fixated, repeated, and unwanted behaviours. Stalking is not an isolated incident and was associated to sexual violence. While the relationship between sexual violence and stalking is scarcely explored, no studies have tested the relationship between stalking and sexual homicide, which both involves elements of obsession. The aim of this paper was to study the relationship between stalking and sexual homicide using an exploratory case study analysis of 7 males convicted for sexual homicide. Results revealed: 1) The presence of obsession prior to the homicide; 2) The victims were ex-intimate partners or acquaintances; 3) The victims were followed several times prior to the index offence; 4) Stalking elements were not always considered by the authorities, which has led to an escalation of behaviours. This study expands our understanding between stalking and sexual violence, supporting the design of prevention and treatments