Incorporating Strengths Into Quantitative Assessments of Criminal Risk for Adult Offenders: The Service Planning Instrument

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.