This book examines the justice gap and trial process for sexual assault against both adults and children in two jurisdictions: England and Wales and New South Wales, Australia. Drawing on decades of research, it investigates the reality of the policing and prosecution of sexual assault offences – often seen as one of the ‘hardest crimes to prosecute’ – across two similar jurisdictions. Despite the introduction of the many reform options detailed in the book, satisfactory outcomes for victims and the public are still difficult to obtain. Cossins takes a new approach by examining the nature and effects of adversarialism on vulnerable witnesses, jury decision-making and the structures of power within the trial process, to show how, and at what points, that process is weighted against complainants of sexual assault, in order to make evidence-based suggestions for reform. She argues that this justice gap is a result of a moralistic adversarial culture which fosters myths and misconceptions about rape and child sexual assault, thus requiring the prosecution to prove a complainant’s moral worthiness. She argues this culture can only be eliminated by a radical replacement of the adversarial system with a trauma-informed system. By reviewing the relevant psychological literature, this book documents the triggers for re-traumatisation within an adversarial trial, and discusses the reform measures that would be necessary to transform the sexual assault trial from one where the complainant’s moral worthiness is ‘on trial’ to a fully functioning trauma-informed system. It speaks to students and academics across subjects including law, criminology, gender studies and psychology, and practitioners in law and victim services, as well as policy-makers.