Blackstone's Senior Investigating Officers' Handbook is aimed at meeting the reference needs of officers who investigate serious, major, and organised crime. It provides step-by-step, easy to understand guidance on all the necessary considerations, procedures, and processes for a Senior Investigating Officer (SIO), whether performing the role at the very outset of an investigation or at the more advanced stages. Chapters include guidance regarding decision-making and the initial response, setting up and managing an investigation, investigative strategies, policy logs, victim, family, and community management, and liaison with the media. There is also instruction on suspect and witness management, conducting 'TIE' (Trace, Investigate, and Evaluate) enquiries, child sexual exploitation and investigating sudden and unexplained infant deaths. Each chapter covers the important areas of a complex investigation with checklists, keypoints, and real-life case studies to help explain the processes and why they are important. All the main investigative foundations, knowledge, and skills for mounting a complex investigation are covered. The sixth edition also includes a new chapter on investigating suspicious missing persons. Each chapter has been completely updated and refreshed to reflect new changes and processes applicable to each individual section. Whether you conduct, review, or take a professional interest in serious and major crime investigation, this title will be an invaluable resource. The first practical guide to this important role, it is commonly referred to as the essential reference book in the wider SIO community (the SIO's bible) and is a highly practical tool for any SIO or prospective SIO.