The authors’ work with the Scottish Police at local and national levels has led to collaborative research and reciprocal training arrangements with police training input for interpreting students and academic input to police officers' training. Consequently, they draw from their experience as trainers of public service interpreters and police professionals working with interpreters to discuss a case study of curriculum design and the development of a didactic model, the interlinked approach, grounded in the reality of a specific local context. The paper reviews the Scottish experience and context which provide a framework for the case study and explores in particular the co-participative nature of the triad (service user, service provider, interpreter) involved in the interpreter-mediated investigative interview. Specific activities based on co-participation are described to demonstrate that the interlinked approach reflects Lave and Wenger’s situated learning model (1991), and that it makes a positive contribution to interpreter and police training as well as PSI research and policy.