Abstract

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

The primary aim of this study is to determine the extent to which the consideration of strengths enhances the predictive validity of risk assessment protocols applied to correctional populations. Data from the Service Planning Instrument (SPIn) Pre-Screen were analyzed for 3,656 adult offenders bound by provincial supervision across Alberta, Canada. The predictive validity of the screening instrument was equivalent across gender and Aboriginal status (areas under the curve [AUCs] = .75-.77). Hierarchical logistic regression revealed significant main effects for risk and strength subtotals in predicting new offenses over 18 months for the overall sample, indicating that the inclusion of strengths adds uniquely to the prediction of recidivism. The overall model yielded a significant Risk Score × Strength Score interaction, illustrating that high strength scores are particularly effective in attenuating recidivism among higher risk cases. Rather than limit their consideration to case management contexts, results support the integration of strengths into quantitative assessments of criminal risk.

Feminist (gendered) pathways theorists maintain that female criminality is largely survival-based, and tied to a constellation of factors including early trauma, ensuing mental health issues, and poverty. Based on items drawn from the Youth Assessment and Screening Instrument, multidimensional scaling was performed to elucidate the respective thematic structure of background and offending characteristics of 663 female and 1,175 male juvenile offenders under community supervision in New York State. Although the gendered pathways theme emerged exclusively for females, a theme closely resembling the traditional antisocial pathway depicted in mainstream correctional literature was also evident among females. Theoretical integration is therefore recommended.

The primary purpose of this study is to introduce the Youth Assessment and Screening Instrument (YASI; Orbis Partners, 2000), which is a comprehensive assessment protocol gauging a range of risks, needs, and strengths associated with criminal conduct in juvenile populations. Applied to a sample of 464 juvenile offenders bound by community supervision in Alberta, Canada, the Pre-Screen version of the instrument achieved a high level of accuracy in predicting both general and violent offenses over an 18-month follow-up period (Area Under the Curve [AUC] = .79). No significant differences in overall predictive validity were found across demographic groups, save for the relatively lower level of accuracy achieved in predicting general reoffending across the subsample of girls (AUC = .68). With regard to strengths, a buffering effect was identified whereby high-risk cases with higher levels of strength had superior outcomes compared to their lower strength counterparts. Results suggest that it is advisable to consider the quantitative inclusion of strength-based items in the assessment of juvenile risk.