Some are unclear whether risk assessment instruments, specifically dynamic risk instruments, have demonstrated utility in the risk estimation, treatment recommendations, and monitoring change over time in men at risk for or under sentence of Indeterminate Detention (ID) for sexual offenses. We compare two datasets, the first consisting of individuals representing a routine sample of persons convicted of a sexual offense and the second of men representative of a high risk/needs sample. These two distinct samples (n = 442, mean Static-99R score = 2.4; n = 168, mean Static-99R score 4.5) were then also scored on the Stable-2007. For both groups this scoring occurred in an institutional setting. The Stable-2007 predicted sexual recidivism in Sample 1 independently and in conjunction with the Static-99R. In the high-risk sample the results were the same. In both samples a compound outcome variable (Sexual + Violent reoffense) was also calculated with the Stable-2007 predicting the compound outcome variable in Sample 1 but not Sample 2. This is interesting in that it suggests that the Stable-2007 assesses constructs specific to sexual re-offense in higher risk offenders and not general traits of violence or common anti-social behaviour. Limitations and directions for further research are discussed.