Pre-determination, or pre-trial, detention is at odds with the presumption of innocence as it subjects individuals to incarceration despite the fact that they have not been convicted of a crime. Despite this, both pre-determination detention and the presumption of innocence coexist in most criminal justice systems. This chapter examines the justifications for pre-determination detention to evaluate whether they are compatible with the presumption of innocence framework developed in the previous chapters. There are three main reasons given for pre-determination detention: type of crime, crime prevention, and to prevent absconding. In addition to these reasons, there are practical issues in international criminal justice which require people to be detained pre-trial despite the fact that the court may prefer to have them released. The chapter argues that of all of these justifications, the only one that might be compatible with the presumption of innocence is to prevent absconding. However, this is only compatible if the determination of whether an accused person might abscond can be decided outside of the context of criminal law and procedure and if there are very specific guidelines regarding how and when this decision should be made.