Blue Line


August 10, 2015
By AndyStuart

by Andy Stuart, Barry S. Cooper, John C. Yuille

An officer pulls over a motorist and walks up to talk to the driver; two officers knock on a residence door to investigate an alleged domestic dispute; two officers approach a group of potential eyewitnesses at a shooting scene; an officer waits in an interview room for a murder suspect.

These four scenarios – although differing in context – share one commonality: they involve police officers about to engage in the task of investigative interviewing, arguably the essence of policing.

What is the ultimate goal? What techniques do experience and the scientific literature suggest should be part of routine interviewing practice? Is it possible to evaluate truthfulness during investigative interviews?
Does evidence-based training assist professionals in becoming more effective interviewers?


Answers to these and other questions form the body of this article, with the objective of providing police with a foundation in which to learn more about the science and practice of effective investigative interviewing.

{The ultimate goal}

Irrespective of whether the interviewee in question is an alleged victim, witness or suspect, the overarching goal of an investigative interview is to gather information about the witness version of events. In the context of interviewing a suspect, in particular, the goal is not to seek a confession, as some non-evidence-based training manuals suggest. A confession may be a consequence of an effective investigative interview but it should not be the goal.

Research on and experience with false confessions is quite clear: some innocent people confess to crimes they did not commit. An effective investigative interview is one protection against false confessions. The goal of an effective interview should be to seek uncontaminated information from the interviewee in a manner that maximizes the quantity and quality of the information provided; that is, the interviewer should cue the memory of the interviewee, not lead their memory (e.g., via leading/suggestive questions).

{The science and practice}

The scientific literature on effective interviewing, coupled with experience, indicates that many investigative interviewers commit one or more errors that collectively have been termed the “sins of interviewing” (see <Yarbrough, Herv‚, & Harms, 2013>). These include, but are not limited to, the following: misunderstanding memory and not planning ahead, considering multiple hypotheses/explanations, establishing rapport and actively listening and observing.

Consider the following adapted example based on a real case. A police officer, recently transferred into a sex crimes unit, was tasked with interviewing a male suspect arrested during a search warrant related to child sexual abuse images. While preparing for the interview – a best practice procedure – he discovered material suggesting the suspect was involved in an online “man – dog love club”. In attempting to introduce this topic early in the interview, he used a joking tone of voice and asked “what is with this dog love stuff?”

In this example, the interviewer committed the “sin” of not establishing rapport and not planning ahead, as he induced shame instead of attempting to elicit guilt. Eliciting guilt can assist in encouraging a suspect to talk about misdeeds but eliciting shame can lead to the opposite result – a suspect ashamed to speak about their actions. The suspect refused to talk at all about the allegations against him. In hindsight and after further training the investigator understood the “sins” he committed and realized his tone of voice and structure of his question made the suspect feel ashamed of his activities.

Fortunately, at a later date, the investigator had a second opportunity when the male was arrested for another sexual offence, and made the most of the interview. He spent more time developing rapport, monitored his tone and questions, showed empathy for the suspect’s situation and learned a great deal of information about the dog fetish.

{Effective interviewing}

Effective investigative interviewing is more than simply not committing “sins” of interviewing. All effective evidence-based investigative interviewing techniques involve, at least at some level, the following factors: preparation, rapport building, cuing memory via non-leading open-ended questioning, using techniques for enhancing memory and considering multiple hypotheses for information observed in an interview (see Cooper, Herv‚, & Yuille, 2014). A few suggested ‘do’s and don’ts’ can be found at the end of this article.

Consider the following adapted real-life example. Two patrol officers are dispatched to a domestic dispute and find a male and female both claiming to be the victim of an assault. The male has a bloody nose and the female has abrasions around her neck. How did the patrol officers determine who was the primary aggressor?

Keeping an open mind to the physical evidence, two hypotheses were considered. The male chocked the female and, to repel the assault, she punched him in the nose. Or alternatively, the female punched the male first and his reaction was to grab her neck.

The most effective way to determine the truth is to conduct interviews. As the fighting had stopped and the officers had to decide what action to take, they interviewed both individuals separately using an audio recorder.

This type of interview was spontaneous in nature (as opposed to planned) and thus little was known about each interviewee. Although most patrol officers would quickly simply ask what happened, unless there is an emergent issue, there is usually an opportunity to first learn about the interviewee by building rapport.

Some obvious areas to discuss include family dynamics, the length and quality of the relationship, others that may reside in the residence, etc., in addition to other investigative questions that would also provide some background to the topic of concern.

Once the interviewee was engaged and appeared ready to tell their story, a free narrative was obtained by asking “tell me what had happened?” This is an example of an open-ended request which allowed the interviewee to tell their story. The interviewer used phases such as “tell me more about that” and asking “what happened next” to move the narrative along while not asking any leading questions.

Afterwards the officers decided a course of investigative action to take based upon all of the evidence, including the interviews. In this case, the evidence received in rapport building led to the questioning of a child witness, who disclosed that the male was a frequent victim of domestic violence and reactively defended himself against his wife’s attack; she was arrested and ultimately charged with assault.

{Interviewing and assessing credibility}

Effective investigative interviewing and evaluating truthfulness are intricately related topics. In fact, the scientific literature and experience suggests it is not possible to reliably distinguish truths from lies without a properly conducted interview (see <Herv‚, Cooper, Schweighofer, & Santarcangelo, 2015>).

Although there is no universal sign of lying, effective interviewing could lead to the elicitation and observation of “hot spots” – changes from someone’s verbal and/or nonverbal “baseline” (i.e., normal) way of behaving (see <Cooper, Herv & Yuille, 2009>). Hot spots are construed as clues to importance and should lead to follow-up questions.

Consider the following adapted real-life case example. A patrol officer was assigned to investigate a sexual assault. The complainant was an 18 year-old female who had called police alleging she was sexually assaulted after responding to an online “room for rent” advertisement.

The officer attended the hospital for a forensic exam and then took the complainant to the detachment for an investigative interview. The complainant produced limited details about the actual sexual assault but was able to provide a lot of information about what happened before and after. Although it is possible for victims of sexual assault and other traumas to be amnesic for all or parts of their experiences (<Herv‚, Cooper, & Yuille, 2013>), the relative lack of detail was viewed as a hot spot.

Attune to the lack of details for the most important part of the event, the officer employed a memory enhancement technique which concurrently served as a credibility assessment tool. In particular, he asked the complainant to tell her story in reverse order, an aspect of the Cognitive Interview (). This was accomplished by asking her to start at the end of her account – “and then I called the police” – and to then recall what happened backwards in time.

The next part of her account could have included statements such as “I ran from the house” and so on. If honest, the backward recall could serve as a memory enhancer as it allows the opportunity to cue her memory to other details that she did not include initially in forward recall. Backward recall could also serve as a credibility assessment tool as honest responders find telling their story in reverse order difficult but not as challenging as for deceptive individuals, who have likely only concocted a lie in the normal – forward – direction.

The complainant stated she could not complete the task. The officer did not confront her at that point but continued with the investigation.

The alleged suspect provided a detailed statement, including time stamped email strings with the complainant showing the sexual nature of their meeting, rather than the initial room for rent version. The officer then challenged the complainant and received an admission – she had made the story up to cover for her whereabouts when confronted by her boyfriend.

{Training on interviewing}

It is clear from the scientific literature and experience that evidence-based training improves practice. There are a number of organizations and individuals that offer training on investigative interviewing with promising results (see <Colwell, Hiscock-Anisman, & Fede, 2013>).

Evidence-based training should include, at a minimum, modules on preparation, criminal behavioural patterns, recording, developing and maintaining rapport, properly phrased questions (e.g., open-ended, non leading), how to introduce the topic of concern, memory and issues concerning credibility.

Ideally, training should be a combination of science and practice and should be tailored to the context (e.g., witness, victim, person of interest, suspect) and interviewee (e.g., child, adolescent, adult, special needs such as cognitive capacity and mental health issues).


Effective interviewing is arguably the essence of policing (and possibly the entire criminal justice system). In most cases, the examination of a defendant in court – another example of an interview – would never transpire without the initial effective investigative interview of a complainant. Thus, the entire judicial process rests on the quality and quantity of the information elicited by various players in the criminal justice system.

<<< Effective Interviewing CHART.tif >>>

Do’s | Don’ts

Prepare for the Interview | Enter the interview blind

Record the interview | Be afraid of transparency

Use a semi-structured tailored approach | Use a cookie-cutter approach

Develop rapport | Fake rapport

Ask the Right Questions at the Right Time | Ask the Wrong Questions at the Wrong Time

Seek truthful information | Seek a confession

Exhaust/Enhance memory | Prematurely end the interview

Understand memory patterns | Assume memory is a simple entity

Understand the motive of the interviewee | Use the “Me” theory

Practice/Seek proper training | Be overconfident

Bibliography/Suggested readings

Colwell, K., Hiscock-Anisman, C., & Fede, J. (2013). Assessment criteria indicative of deception: An example of the new paradigm of differential recall enhancement. In B.S. Cooper, D. Griesel, & M. Ternes (Eds.), (pp. 259-291), New York: Springer.

Cooper, B.S., Herv‚ H., & Yuille, J.C. (2009). In R. Bull, T. Valentine, & T. Williamson (Eds.), (pp. 301-328), Chichester, UK: Wiley-Blackwell.

Cooper, B.S., Herv‚, H., & Yuille, J.C. (2014). Evaluating truthfulness: Interviewing and credibility assessment. In D. Wesiburd & G. Bruinsma (Eds.), (pp. 1413-1426), New York: Springer-Verlag.

Fisher, R.P. & Geiselman, R.E. (1992). Springfield, Illinois: Charles C. Thomas.

Herv, H., Cooper, B.S., Schweighofer, A., & Santarcangelo, M. (2015). Assessing and treating sexual offenders: The importance of effective interviewing and evaluating truthfulness. In B. Schwartz (Ed.) Volume 8 (pp. 7-1 – 7-42), Kingston, NJ: Civic Research Institute.

Herv, H., Cooper, B.S., & Yuille, J.C. (2007). Memory formation in offenders: Perspectives from a biopsychosocial theory of eyewitness memory. In S.A. Christianson (Ed.), <Offenders’ memories of violent crimes> (pp. 37-74), Chichester, England: John Wiley and Sons.

Herv, H., Cooper, B.S., & Yuille, J.C. (2013). Biopsychosocial perspectives on memory variability in eyewitnesses. In B.S. Cooper, D. Griesel, & M. Ternes (Eds.), (pp. 99-142), New York: Springer.

Yarbrough, J., Herv, H., & Harms, R. (2013). The sins of interviewing: Errors made by investigative interviewers and suggestions for redress. In B.S. Cooper, D. Griesel, & M. Ternes (Eds.), (pp.59-95), New York: Springer.

Yuille, J.C., Cooper, B.S., & Herv‚ H.F. (2009). The StepWise guidelines for child interviews: The new generation. In M. Casonato & F. Pfafflin (Eds.), <Pedoparafile: Psychological perspectives, forensic psychiatric> (published in Italian). Italy: Franco Angeli.

Yuille, J.C., Marxsen, D., & Cooper, B.S. (1999). Training investigative interviewers: Adherence to the spirit, as well as to the letter. 22(3-4), 323-336.


Andy Stuart is a member of the Saanich Police Department and The Forensic Alliance

Barry S. Copper is a member of The Forensic Alliance, the University of British Columbia, Simon Fraser University and the Forensic Psychiatric Services Commission.

John C. Juille is a member of The Forensic Alliance and the University of British Columbia.

Contact Andy Stuart at 250-812-4913 or for more information.