Make no mistake about it, investigative interviewing and criminal interrogation are complex, psychologically demanding tasks. Understanding human nature and the dynamics of communication along with knowing the rules of persuasion and influence, listening to verbal behavior, observing non-verbal signals and paralinguistic cues as well as documenting any physiological changes, grooming gestures, emblems, and micro-expressions of emotion you observe during the interview can be overwhelming. Understandably, it is easy to miss much of what is going on during the interview or interrogation, let alone knowing what the subject said.
But as with almost any task regardless of how complex, there are basic aspects which will be responsible for the majority of your success. Quite simply this is the "80/20 rule" which states that approximately 80% of your success will come from about 20% of your activities. Within the area of investigative interviews and criminal interrogations we can break that down into three main ingredients, if you will, which if present within your interviews and interrogations will greatly enhance your ability of a successful outcome by obtaining as much truthful information the subjects has within his or her memory.
1) Do your background: One of the fundamentals of effective interviewing is knowing the facts of your case and the strength of any available evidence. Have you ever been asked at the last minute to fill in on an interview or interrogation for a detective who may have been tied up on another task, and you get the "5-second briefing" before walking into the interview room? How effective can you be in that situation? The reality is, not very. You will just be the scribe and learn as you go along during the interview process. As investigators, we can be much more effective individually and as a team when we plan and prepare for the interview or interrogation well in advance of walking into the room by conducting a thorough case review and developing an interrogative strategy.
Planning and preparation while developing background information also includes knowing as much as possible about the individual you will be talking with. What is this individual’s background? Prior arrests? Married? Children? Pets, Hobbies? Social circles? Religious beliefs? Gang affiliations? and on, and on. The more you know about the individual, the better your chances are of developing rapport and gaining the individuals trust and cooperation.
2) Ask open questions: By open questions I am referring to questions such as, "tell me everything that happened yesterday from the time you woke up until you ended your day", or "describe in detail everything that happened regarding the assault", or "tell me about your relationship with Mr. Johnson." Questions like these are open-ended, allowing for the individual to provide a free narrative response without any influence from the interviewer. Part of the importance of this type of question is that we obtain information rather than give information away, and there is limited contamination from the question itself. Asking a question such as "were you at Bob's Burger Barn yesterday at 2:00?" instantly tells the subject important facts about your investigation such as 'time' and 'location'. Now the individual can easily construct an alibi covering where he was yesterday at 2:00, if he hasn't planned it out already, and sometimes it may be unverifiable making it difficult to dispute it. However, if the individual responds to an open question such as "tell me everything that happened yesterday from the time you woke up until you ended your day" and they interject the time of the crime on their own, that may be significant. Why did they choose to put that specific time in their statement? After obtaining the initial response from an open question, whether in a written statement or an oral interview, you then review and ask clarifying questions to expand upon what they stated, again, using an open-question style such as "tell me more about...", or "you stated you arrived at the party at 7:30, describe in detail everything that happened upon your arrival." Continue to ask clarifying, memory-probing questions to develop the information that the individual provided.
3) Listen to what they say: This by far is one of the most important aspects of conducting effective investigative interviews or criminal interrogations. It seems rather obvious, but in practice, many investigators do not really listen to what the individual said. Often times the investigator is working down a list of questions and while the individual is responding to one question, they are already thinking about the next question they plan on asking. Also, sometimes the investigator is so caught up in looking at the non-verbal behavior, eye movements, hand and foot movements, 'lint-picking' or other grooming gestures and trying to assess what that all means, but the verbal cues are being missed.
The importance of this cannot be understated because much of the recent research on deception has indicated that verbal cues are more diagnostic of deception than non-verbal cues. Researchers have recommended that police focus on what people say rather than what they do during interviews since it has been shown that truthful accounts differ from fabricated accounts in various ways which can be identified by really listening to their account. Also, by understanding principles of investigative statement analysis and by really listening to the words the individual uses, you will be able to discern subtle differences in the content of their language and word choices leading to a better assessment of their veracity. Sometimes what appears to be a denial may not be, but it can be easily missed if you do not pay attention to the individual’s language.
In summary, there are certainly no short-cuts to conducting effective interviews or interrogations, and it is my opinion that the more training you have and the more experience you gather from the application of the techniques and information, the more effective you can be. I strongly suggest attending all the training classes and seminars you can to enhance your interview and interrogation skills. However, by applying the basic principles above such as obtaining as much background information on the case and the individual as possible, and developing rapport and trust with them, and ask open-ended questions geared towards information gathering, and really listen to their responses, you will be 80% there.