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Model of Static and Dynamic Sex Offender Risk Assessment

NCJ Number
Date Published
October 2011
96 pages
This study tested models that combined static and dynamic risk measures that might predict sexual recidivism for adult male sex offenders better than any one type of measure alone.
The study found that a logistic regression model that combined measures from both dynamic and static risk instruments consistently predicted recidivism and outperformed either instrument alone when both instruments had similar predictive power. Static risk factors are unchangeable aspects of an individual's history; whereas dynamic risk factors are potentially changeable. Risk-needs instruments assist treatment providers in determining those aspects of an offender's behavior, attitudes, and needs (dynamic factors) that are susceptible to change that leads to the reduction or elimination of reoffending. A relatively small number of integrated sex offender risk-needs models now exist in which dynamic risk factors inform rehabilitation and case-management efforts so as to add incremental predictive validity to static risk factors. The current study confirmed that the assessment of dynamic risk factors at regular intervals during the course of services may be significant in helping providers adjust the intensity and duration of interventions. This study used a repeated measure paradigm over the assessment periods with a sample of 759 adult male sex offenders enrolled in community treatment in Vermont between 2001 and 2007. These offenders were assessed once using static measures (Static-99R, Static-2002R, and VASOR) based on participants' history at the date of placement in the community. A 22-item dynamic risk measures (Sex Offender Treatment Needs and Progress Scale) was used multiple times to assess participants shortly after their entry into community treatment and approximately every 6 months thereafter. Analyses of the dynamic assessment scores resulted in the development of a new 16-item dynamic risk measure, the Sex Offender Treatment Intervention and Progress Scale (SOTIPS), which was used at 1-year and 3-year follow-up periods. 28 tables, 2 figures, and 76 references

Date Published: October 1, 2011