Book excerpt: Providing a comparative analysis of both vulnerable witnesses and vulnerable suspects, this book discusses the increasingly difficult issue faced by many in modern policing, forensic psychology, criminology, and social justice studies. Examining recent legislation, guidance, current psychological theory, and contemporary research and literature, the book enhances the currently limited knowledge of vulnerability in the criminal justice system (CJS) through the presentation of theoretical understanding, case law and real-life case studies. It also explores how vulnerable victims, witnesses, and suspects progress through the system in England and Wales from initially being identified as vulnerable through to the measures used to assist them during interviews and at trial. In doing so, it provides a historical overview of how vulnerability has previously been considered, and how effective those with vulnerabilities were perceived to be in actively participating in the CJS. Further chapters consider how vulnerable individuals are safeguarded, the differences in services available to them, and what this may lead to in terms of effective participation in the system. How vulnerable groups are interviewed, what is considered best practice, and whether such practices are suitable also come under scrutiny. Exploring Vulnerability in the Criminal Justice System in England and Wales is important reading for students and scholars of policing, forensic psychology, criminology, and social justice studies. It will also be of use for any organisations that conduct internal investigations such as non-government organizations, security and defence organisations, and corporate organizations.