Preventative detention: Asking the fundamental questions

If a person poses a risk to society, why not lock them up before they do something bad? If they haven't been rehabilitated in prison, why let them out? These questions have vexed governments throughout the world. 'Preventive detention' is now widely used for the management of'dangerous people', particularly terror suspects and sex offenders. The chapters of this volume examine preventive detention jurisprudence in Australia, Germany, New Zealand, the United Kingdom and the United States and address the fundamental questions that need to be asked and answered when governments consider whether to introduce these regimes:
*Can preventive detention regimes be consistent with human rights?
*Are our risk assessment methodologies sufficiently reliable to justify preventive detention orders?
*Are there policy alternatives to preventive detention?

In their important chapter in this volume, Arlie Loughnan and Sabine Selchow have challenged preventive detention scholars to go further: to go 'beyond traditional legal concerns and a concern for effectiveness, to ask what preventive detention does to society' (emphasis added). I briefly address that question at the end of this chapter, which defines key concepts and themes used in this collection.