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Abstract

It is hypothesized that stranger rape victim statements will reveal a scale of violation experienced by the victim, ranging from personal violation, through to physical violation, and finally, at the most extreme level, sexual violation. It is also hypothesized that offences can be differentiated in terms of one of four themes: hostile, controlling, stealing, or involving. To test these hypotheses, crime scene data from 112 rapes were analyzed by the multi-dimensional scaling procedure Smallest Space Analysis. The results provide empirical support for a composite model of rape consisting of four behavioral themes as different expressions of various intensities of violation. The results also suggest that stranger rapes may be less about power and control than about hostility and pseudo-intimacy. The proposed model has implications for the classification of rape, the investigation of sexual crimes, and the treatment of victims.

Purpose. Through an examination of serial rape data, the current article presents arguments supporting the use of receiver operating characteristic (ROC) analysis over traditional methods in addressing challenges that arise when attempting to link serial crimes. Primarily, these arguments centre on the fact that traditional linking methods do not take into account how linking accuracy will vary as a function of the threshold used for determining when two crimes are similar enough to be considered linked.Methods. Considered for analysis were 27 crime scene behaviours exhibited in 126 rapes, which were committed by 42 perpetrators. Similarity scores were derived for every possible crime pair in the sample. These measures of similarity were then subjected to ROC analysis in order to (1) determine threshold-independent measures of linking accuracy and (2) set appropriate decision thresholds for linking purposes.Results. By providing a measure of linking accuracy that is not biased by threshold placement, the analysis confirmed that it is possible to link crimes at a level that significantly exceeds chance (AUC ¼ :75). The use of ROC analysis also allowed for the identification of decision thresholds that resulted in the desired balance between various linking outcomes (e.g. hits and false alarms).Conclusions. ROC analysis is exclusive in its ability to circumvent the limitations of threshold-specific results yielded from traditional approaches to linkage analysis. Moreover, results of the current analysis provide a basis for challenging common assumptions underlying the linking task.Of paramount importance in police investigations is the ability to accurately link crimes committed by the same offender. The correct identification of an offence series allows investigators to pool information from all relevant crime scenes, thus resulting in a more efficient use of investigative resources (Grubin, Kelly, & Brunsdon, 2001). Despite the practical importance of this task, it has been the subject of limited empirical research. In fact, it has only been in the last decade that any notable effort has been made to

Geographic profilers have access to a repertoire of strategies for predicting a serial offender's home location. These strategies range in complexity-some involve more calculations to implement than others-and the assumption often made is that more complex strategies will outperform simpler strategies. In the present study, we tested the relationship between the complexity and accuracy of 11 strategies. Data were crime site and home locations of 16 UK residential burglars who had committed 10 or more crimes each. The results indicated that strategy complexity was not positively related to accuracy. This was also found to be the case across tasks that ranged in complexity (where complexity was determined by the number of crimes used to make a prediction). Implications for police' policies and procedures, as well as our understanding of human decisionmaking, are discussed.