This unique text provides police officers with practical guidance on what to do prior to, during, and following investigative interviews of all kinds of witnesses, from vulnerable adults and children to suspects. It explains the psychological underpinning of the Conversation Management technique which lies at the heart of the PEACE interviewing model. It offers a comprehensive tool-kit to help officers skillfully assess and monitor the interviewee and to capture the fine-grain detail of what is said, or indeed not said, in an interview. It advises officers on how to operate ethically and to maximum effect at each phase of interviewing. This highly accessible text contains a variety of useful features including checklists, best practice and handy dialogue boxes, providing 'how to' guidance on interviewing vulnerable and non-vulnerable witnesses, child witnesses, and suspects. It is intended to complement the courses that police officers attend as part of their interview training including tiers 1-5, Vulnerable Witness Interviewing and PIP.