Stranger sexual homicide: an exploratory behavioural analysis of offender crime scene actions

ABSTRACT

This study explores the role and function of homicidal and sexual violence in cases of stranger sexual homicide. The aim was to determine whether the instrumental/expressive hypothesis of physical violence and the overt/covert hypothesis of sexual violence applies to this crime. The method involved an analysis of the crime scene actions of 81 British stranger sexual killers using multidimensional scaling. Results suggest the instrumental/expressive hypothesis of physical violence and the overt/covert hypothesis of sexual violence does apply to stranger sexual homicide but they manifest as instrumental/overt and expressive/covert superordinate themes comprising four sub-themes reflecting rape, impersonal sexual assault, overkill and control. Although these superordinate themes can explain some stranger sexual homicides, a key hypothesis of this study is that the four sub-themes can also combine into different superordinate themes, knowledge of which can aid our understanding of this serious and deviant form of interpersonal violence.

KEYWORDS:

• Stranger sexual homicide
• sexual murder
• classification
• formulation
• crime scene analysis

Acknowledgements

The authors are grateful to the editors of this Journal for their useful comments on earlier drafts of this paper.

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes

1 Severe injuries involve serious single or repeated blows that require hospitalisation and that could have contributed to the death e.g. the victim repeatedly punched to the face, rendered unconscious and hospitalised. Extreme injuries involve violence beyond that necessary to cause death.

2 All data inputted onto the SCAS ViCLAS database in the UK is completed in-house in a controlled environment by a team of highly trained individuals. Applicants are tested for their attention to detail and ability to identify relevant information prior to employment with SCAS. Recruits undergo several months of training before they are allowed to work autonomously, and only after they obtain a highly detailed knowledge of the system. To ensure accuracy and knowledge the training is rigorous and lengthy, and recruits must show clear understanding of behavioural vagaries. Initial training is not undertaken on a live database, and staff will not begin working on the live database until they have evidenced their capability to complete inputs accurately. Ensuring consistency in decision making in relation to difficult issues, a 'Quality Control Guide' is utilised by everyone inputting data on the database. Where an unusual aspect is encountered, for which no precedent has been set, a dedicated, experienced team meets to review the situation and make a decision. This decision is then recorded for future reference to ensure future consistency. Additionally, each inputted case goes through a detailed quality assurance process prior to any analysis taking place. This involves a review of the inputted information in comparison to case details, by an analyst from within the team and anomalies or errors are fed back to the inputter and amended on the database.