Police interviewing is a critical part of the justice process, and more attention is now being paid to training in interview techniques. This new study from Australia uses tools drawn from interactional sociolinguistics and Conversation Analysis for a detailed investigation of some police questioning of adult suspects, and work undertaken in the training of police in interviewing children - in which quite different approaches seem to be adopted. The study powerfully illustrates the conflicts and contradictions that threaten to undermine the success of criminal proceedings and presents a fresh perspective on the balance between civil liberties and police power. Critical Discourse analytic techniques are used in interpreting the outcome. Both productive and counterproductive police interview strategies are exposed and the implications for interview training are explored.