Whereas crime more generally has fallen over the last 20 years, levels of serious youth violence remain high. This book presents innovative research into the complex relationship between adverse childhood experiences and serious youth violence. While the implementation of trauma-informed approaches to working with adolescents in the justice system is becoming common practice, there remains a dearth of research into the efficacy of such approaches. Foregrounding young people's voices, this book explores the theoretical underpinnings of trauma and the manifestations of childhood adversity. The authors conclude by advocating for a more psychosocial approach to trauma-informed policy and practice within the youth justice system.