No matter what kind of interrogation you’re doing, an investigator or interviewer needs to quickly establish a rapport with a person. Colin McLaren advises Eve Ash that this can be done through being informal (removing jacket), offering a beverage or lunch (if the interview will be long). He counsels not trying to be tough or raising your voice or resorting to abrupt body language. An interviewee is offering information voluntarily and will only do so if not feeling threatened by the interviewer.
Colin McLaren emphasizes the importance of rapport in conducting an investigation interview:
Create rapport at the start of an interview
Offer the interviewee a coffee, and if a long interview, a sandwich
