let them know that you will be concluding the interview by asking them whether they have anything to say or wish to ask you. Remember the golden rule that under no circumstances can you use force or threats or even inducements to encourage a suspect to speak if they choose to exercise their right to remain silent. Practical testing Too often success in police training is measured by the existence of a training course, levels of attendance or completion, or the overall numbers participating. Of course, it is entirely possible for officers to attend such courses and either not acquire the appropriate skills and knowledge or quickly desist from applying what they have learned in the classroom in their professional practice. Therefore, there is a need for officers to be assessed during and shortly after undertaking any course in investigative interviewing and at a later point in their practice (perhaps 12 to 18 months later) to see if they are consistently applying the knowledge, skills and principles at the heart of investigative interviewing. A great deal depends upon proper supervision, constructive support and feedback being made available to police interviewers. It is good practice to create a supportive, learning environment in which inexperienced officers can call upon more experienced interviewers (including supervisors) to aid them in conducting interviews at any stage of the process. It may be necessary to involve more experienced and adept colleagues in leading the interview. This particularly applies where the person being interviewed presents special challenges or the case is of a particularly serious or complex nature. Page 20 ► A brief introduction to investigative interviewing