Improving risk assessments for sex offenders: A comparison of three actuarial scales

The study compared the predictive accuracy of three sex offender risk-asses sment measures: the RRASOR (Hanson, 1997), Thornton's SACJ-Min (Grubin, 199 8) and a new scale, Static-99, created by combining the items from the RRAS OR and SACJ-Min. Predictive accuracy was tested rising four diverse dataset s drawn from Canada and the United Kingdom (total n = 1301). The RRASOR and the SACJ-Min showed roughly equivalent predictive accuracy, and the combin ation of the two scales was more accurate than either original scale. Stati c-99 showed moderate predictive accuracy for both sexual recidivism (r = 0. 33, ROC area = 0.71) and violent (including sexual) recidivism (r = 0.32, R OC area = 0.69). The variation in the predictive accuracy of Sratic-99 acro ss the four samples was no more than would be expected by chance.