This book offers a history of the development of forensic sciences, centred on the UK, but with consideration of continental and colonial influences, from around 1880 to approximately 1940. This period was central to the formation of a separate discipline of forensic science with a distinct professional identity and this book charts the strategies of the new forensic scientists to gain an authoritative voice in the courtroom and to forge a professional identity in the space between forensic medicine, scientific policing, and independent expert witnessing. In so doing, it improves our understanding of how forensic science developed as it did. This book is essential reading for academics and students engaged in the study of criminology, the history of forensic science, science and technology studies and the history of policing.