As with all areas of police activity, questions of governance, accountability and ethics are among the most important. Given what we had to say in the Introduction to this book about the less than entirely happy history of police criminal investigation, there can be little doubt about the importance of such issues in this area. In the opening chapter, Peter Neyroud and Emma Disley look at some of the issues involved in the management, supervision and oversight of criminal investigation. They identify four dimensions: the coordination of the elements and processes of an investigation; the supervision and leadership of police officers and staff conducting investigations; performance management; and, finally, the systems of oversight of such investigatory activity. Some of these areas have been the subject of relatively limited academic inquiry. However, all four have recently been the subject of considerable policy development. Almost certainly, what is now required is further systematic research on the effectiveness of the new systems and procedures that Neyroud and Disley outline.