This Handbook is one of a series of tools developed by UNODC to support Member States in the implementation of the rule of law and the development of criminal justice reform. It is designed to be used by prison managers and prison staff, in particular, but will also be relevant for other actors involved in the criminal justice system, such as policymakers, legislators and members of non-governmental organizations. It can be used in a variety of contexts, both as a reference document and as the basis for staff training. While some elements of the Handbook may not be achievable immediately in some jurisdictions, particularly in postconflict situations, the Handbook provides national authorities with guidelines for the development of policies and protocols that meet international standards and good practice. This Handbook constitutes the first technical guidance tool to addresses the manifestation of radicalization to violence and violent extremism in prison settings at the level of the United Nations. It provides practical guidance on: The management of violent extremist prisoners (prisoners who have embraced violent extremism). Preventing the progression to violent extremism in prisons (prisoners who may be vulnerable to radicalization to violence). Interventions aimed at disengaging violent extremist prisoners from violence and at facilitating their social reintegration upon release. Within these parts, the Handbook covers key prison management policies and mechanisms, such as the need for: overall prison conditions to be in line with international minimum standards; effective assessment and classification systems; physical, procedural and dynamic security; professional prison staff training; fair, humane and non-discriminatory treatment; preventing corruption; various categories of disengagement interventions involving experts from different disciplines; and social reintegration and post-release support.