At Oxford University Press, Katie Allan and Andrea Oliver brought the first edition into being; Peter Daniell, Lindsey Davis, and Jodi Towler, the second; and for their commissioning, assistance and guidance with the third edition we are grateful to Peter Daniell, Lucy Alexander, and Emma Hawes. Their support, patience, and understanding, particularly when unforseen circumstances interrupted revision and production of this third edition, is much appreciated.

Professor Emeritus John Grieve CBE QPM (former Deputy Assistant Commissioner, Metropolitan Police Service and currently Independent Monitoring Commissioner for Northern Ireland), as ever, has been a pillar of strength and support and a source of inspiration.

The new edition of this book continues to provide a practical, introductory guide for anyone working in the area of covert investigation. This edition is updated to include new draft codes of practice to RIPA, new thinking on risk management, and updates to case law. It also offers discussion on the interpretation and implementation of covert powers subsequent to the outcome of the Home Office review. The book contains all the relevant legislation, codes of practice and case-law relating to covert investigation methods and examines the issues that investigators need to consider when deploying such investigative tools, concentrating on the full implications of RIPA with regards to daily, routine policing activity. The authors considers each different aspect of covert investigation in turn, discussing statutory provision and introducing case law alongside investigation management issues. It successfully demystifies an area of investigation and enforcement that has hitherto been poorly understood.It is intended to assist those planning and supervising investigations and those with a statutory obligation to sanction applications for authorised covert investigation or withhold such authority. It will help officers improve the quality of RIPA applications, ensure that applications for cover investigation are made only in appropriate circumstances, and to help investigators apply the law and procedure correctly in order to minimise procedural challenges at court. The book forms part of the Blackstone's Practical Policing Series. The series, aimed at junior to middle ranking officers, consists of practical guides containing clear and detailed explanations of the relevant legislation and practice, accompanied by case studies, illustrative diagrams and useful checklists.