The problems associated with groups that commit crime are well known and notoriously complex. However, there are many questions that we still cannot answer with certainty. This book seeks to deepen understanding of the group processes involved in crime and the treatment of offenders' thoughts and behaviour. Together, the chapters in this volume address the following questions: * Are people more likely to commit crime because of the influence of their group? * Does group membership cause people to become criminals, or does the group merely foster people's pre-existing criminal inclinations? *...