Youth Justice is an expanding field. Over the past few years, not only has it drawn in new groups of professionals and volunteers, but also it has affected the ways other agencies and organisations work with young people in trouble. While those working in mainstream youth justice and these other agencies will know something about this complex and constantly changing field, few will feel that they know enough. It is to this broad audience that The RHP Companion to Youth Justice is directed. The RHP Companion to Youth Justice is a key point of reference for professionals, trainees, volunteers and students undertaking the youth justice training introduced by the Youth Justice Board of England and Wales in 2003/2004, and other relevant forms of training and education, because it offers the most comprehensive and authoritative account of this complex field available; and it does so in an easily digestible form.