Objectives of the interview
Before starting an interview, the objectives of the interview should be explained to the interviewee, and they should be provided with an outline or route map of it.
For example, interviewers may say:
‘During this interview I will talk to you about (list objectives).’
Then go on to explain:
‘I will also ask you about anything else which may become relevant during the interview in order to properly establish the facts and issues.’
Routines and expectations
It is good practice to explain to the interviewee that if they nod or shake their head the interviewer will state that they have done so. It should also be explained that notes will be taken during the interview.
It may be useful to inform the interviewee that although the police wish to establish certain facts and issues, it is the interviewee’s opportunity to explain their involvement or non-involvement in the incident under investigation.
Investigators should encourage the interviewee to voice anything which they feel is relevant, explaining that there is no time limit for the interview and that as much detail as possible is required, encouraging the interviewee to voice anything which they feel is relevant.
The interviewee should be reassured that they will not be interrupted. It may be appropriate to ask the interviewee to consider fully any question they are being asked before they answer.
https://www.app.college.police.uk/app-content/investigations/investigative-interviewing/#planning-and-preparation