Does torture prevention work? The question that we address in this book is both simple and generally neglected. A number of associated questions have been debated widely. What causes torture? Do democracies torture less than autocracies? Does ratifying a treaty reduce torture? These questions are important and have a bearing on the question we are asking. But our focus is narrower. In recent decades, treaties have required states to adopt a series of preventive measures in order to reduce the risk of torture. These measures, originally inspired by common sense and practices that seemed to work, have not been systematically tested. That is what we do in this study.

We look at four groups of preventive measures, all regularly listed in the recommendations that international bodies and human rights advocates make to states. Contemporary discussion of ‘torture prevention’ focuses heavily on national and international monitoring mechanisms that visit places of detention and imprisonment to inspect conditions and review procedures. A template for both national and international monitoring bodies is provided by the Optional Protocol to the United Nations Convention against Torture and Other Cruel, Inhuman, or Degrading Treatment or Punishment (OPCAT).

Monitoring, and OPCAT, are one element of the prevention puzzle. Alongside this, complaint mechanisms are also often advanced as examples of preventive mechanisms. National human rights institutions, which usually combine complaints and monitoring, have grown rapidly over the past 25 years, partly in response to a sustained United Nations agenda to promote such bodies.

A third element, set out in the United Nations Convention against Torture and Other Cruel, Inhuman, or Degrading Treatment or Punishment (Convention against Torture), focuses primarily on state jurisdiction over the crime of torture and the prosecution of torturers. It too is intended to be preventive and fits the model of other international crime prevention treaties. Finally, laws, rules, and procedures that govern the arrest, detention, and interrogation of suspects are considered by many to be essential because they reduce the opportunity for police and other security officials to torture.