Static-99R Norms and Cross-Cultural Validity for Australian Aboriginal and Non-Aboriginal Men Convicted of Sexual Offences.

Abstract

This study examined Static-99R normative data and cross-cultural validity in a sample of 811 Aboriginal and 3257 non-Aboriginal Australian men (N = 4068) serving custodial orders for sexual offences in New South Wales (NSW), Australia. Aboriginal men scored significantly higher on the Static-99R than non-Aboriginal men (M = 4.39 vs. 2.61) and were more likely to be represented in higher categories of risk. The Static-99R showed good discrimination performance for the total sample (AUC = .76; 95% CI = [.73-.80]) and acceptable calibration to expected reoffending rates for routine samples, with slight tendencies towards overestimation. Discrimination accuracy was lower for Aboriginal men (AUC = .68; 95% CI = [.60-77]) than non-Aboriginal men (AUC = .78; 95% CI = [.74-83]) although was significantly better than chance for both groups. Additional analyses indicated that cross-cultural differences in discrimination were partly associated with variance in sample composition between groups. This is the first Australian study to find evidence for significant predictive validity of the Static-99R with Aboriginal men, and while further research is needed, the results provide initial support for cross-cultural applications of the measure in local criminal justice settings.