The new preventive detention is put to the test. Due to the earthshaking Federal Constitutional Court decision of May 4th, 2011, new regulations of preventive detention became necessary. Well over three years after the reform the anthology takes a closer look at the new legal situation in an interdisciplinary manner and with due regard to the exchange between science and practice. It focuses not only on the new law and its implementation in practice, but also on ongoing problems and the demand for further legal reforms. Main topics are, inter alia, empirical findings on the development of preventive detention, risk and transition management problems that arise when detainees are released from preventive detention, the search for alternatives to preventive detention, impacts of the new legal situation on the general penal system, the relation between preventive detention and criminal defense, the unsolved problem of predicting future crime as well as pending research questions in the field of sanctioning “dangerous” offenders.