Let's say this is Luther, I always end up with DCI Luther for some reason, and he has arrested a suspect and taken them straight back to the police station, booked him/her into custody via the custody officer during which he would have to explain what he has arrested the suspect for, what the evidence is for the arrest and what he intends doing next which will be interviewing. In real life this process, unless urgent and authorised by a Superintendent which allows for limited questions in certain circumstances see "A Confession" as an example when this was used, would mean Luther would have to wait for a number of hours before he would get to interview the suspect. I will cover custody issues in a later blog as that is a large subject area on it's own.
So let's move on to the actual suspect interview. What is important for the writer is to firstly establish how that interview will be recorded? During my service I saw many changes to this process from writing notes, to writing a full transcript of the interview, to cassette tapes recording the interview and moving on to DVD recordings of the interview being video captured. Along the way the police have tried other methods such as streaming the interview to a typing pool where it was typed ready for being reviewed if required by another officer or lawyer. As a side note CPS lawyers when reviewing the case would never watch or listen to an interview they would read a transcript produced by the police as other wise it would be too time consuming. It may be that one portion of the interview which contains a relevant piece of material would be viewed or listened to but even this is unlikely unless it was to be used at court.