Study findings were consistent with previous research results in terms of criminal prognosis. The current data support the hypothesis that the main group of offenders in preventive detention consists of socially disintegrated offenders with problematic personality traits and even personality disorders. Eleven percent of the sexual offenders with an order of preventive detention showed previous orders of treatment in a forensic psychiatric clinic and 4 percent had received previous treatment in a therapeutic institution for substance addictions, which indicated that the discrimination between offenders with or without forensic psychiatric impairments was not easy to make. The analysis showed a high rate of psychiatric expert testimonies' lacking basic information with an incomplete assessment of sexual history. Additional research is recommended to determine whether this has led to an underestimation or overestimation of risk, and to improve the quality of psychiatric statements concerning sexual offenders. Preventive detention is primarily a measure of security, not treatment. Preventive detention is executed after the offenders have served their sentences. It can be terminated when the "risk" of further offenses is deemed to be small. In the last decade, preventive detention, especially relating to sexual offenders, has gained relevance for the German legal system. However, release became complicated because the maximum term of 10 years was abolished for sexual offenses and dangerous offenses and the prognosis for release was bound up with lacking "risk," resulting in rapidly growing numbers of inmates. This study sought to provide information and clarification concerning the inmates and expert opinion practice. Court orders and psychiatric statements of 114 offenders with orders of preventive detention were examined, 57 of who were incarcerated because of sexual offenses. Tables and references