This study examines the recidivism of offenders who are considered to be highly dangerous but who, as a result of a decision of the German Federal High Court, have not been in preventive detention because it was imposed retrospectively (Group II preventive detention cases; § 66b StGB). Taking into consideration the restrictions imposed by the study, the data were evaluated regarding their usefulness for predicting the likelihood of reoffending. The results of this study suggest that it could be useful to describe criteria for the not very severe reoffending group. Copyright © 2013 John Wiley & Sons, Ltd.