This introduction presents an overview of key concepts discussed in the subsequent chapters of this book. The book set out in two sections, namely; Policing Research in Context and Inside Policing. The first section sets out the context in terms of the political and theoretical influences on policing research, through to key themes in professionalisation and privatisation. Peter Squires outlines the changes in police research with changes in policing from a commentary of the sociology of policing through to the development of crime science. The second section inside policing explores empirical policing research in a particular context from policing and sexuality through to the ethical challenges facing researchers. It also helps policing scholars and students prepare their own research plans by providing critical reflection of conducting research while also illustrating examples of the unexpected in policing research.