The purpose of the present research was to evaluate preventative detention legislation in Canada by a) comparing designated offenders to non-designated offenders in terms of risk and comparing both designated groups in terms of treatment amenability, b) examining the risk assessment reports that informed the judges’ decisions by comparing prosecution-retained versus court-appointed expert assessments, and c) evaluating the reasons for sentencing to assess the variables most important to the final designation outcome. The sample sizes for the three studies were as follows: Study 1 = 58
dangerous offenders (DOs), 129 long-term offenders (LTOs), and 562 flagged offenders; Study 2 = 43 prosecution-retained expert assessments, 68 court-appointed expert assessments; Study 3 = 31 DO decisions and 55 LTO decisions.

From Study 1 it can be concluded that the preventative detention legislation appears to be correctly applied in that a) DOs and LTOs were a higher risk group compared with flagged offenders, b) DOs and LTOs were similarly rated as high risk on validated risk measures, and c) DOs and LTOs differed on indices of treatability and risk management. Results from Study 2
demonstrated that across all comparisons, risk assessment reports between prosecution-retained versus court-appointed experts were more similar than they were different. Results also demonstrated that court-appointed experts were more likely than prosecution-retained experts to list risk factors and to discuss managing the offender’s risk in the future. Results from Study 3 demonstrated that judges’ decisions were consistent with expert assessments in terms of risk, treatment amenability, and risk management. Experts’ ratings of treatment amenability and risk management were also significant
predictors of the designation outcome indicating that judges rely on this information in making their final decision. Finally, there was evidence of partisan allegiance with prosecution-retained Hare Psychopathy Checklist-Revised scores being significantly higher compared with defence-retained experts’ scores. Implications of the results from all three studies are discussed in terms of the validity and appropriate application of preventative detention in Canada.