This book examines how the police make decisions in real life situations, particularly in major enquiries. The two key themes explored are real-time decision making along with what "works" in such circumstances. It aims to set out how successful decisions are arrived at in a variety of difficult and time-constrained situations and discusses the lessons that can be learnt from this. Written by practitioners and academics, the book explores a range of topics, from the decision making process involved operational matters and in difficult-so-solve murder enquiries. It not only examines decision making but also how experienced decision makers function. It looks at the psychology of police decision making, decision making involved in cold case investigations, and discusses the need for "grip" during major investigations. The contributors are experienced and respected practitioners and academics This book will appeal particularly to those studying Policing and Criminology and also to Investigating Officers and those involved in professionalising investigative practice.