Adult forensic interviewing techniques

This report is currently under review.

This report is currently under review.

This report is currently under review.

This section provides an overview of three forensic interviewing techniques for adult vulnerable victims who are interviewed in a forensic or investigative context. In Canada, there are no national standardized protocols for interviewing adult vulnerable victims, so the protocol used by investigators may differ depending on the location and type of incident.

The protocols covered in this section represent three of the most-used techniques in the field: the Cognitive Interview (CI), the Forensic Experiential Trauma Interview (FETI), and the Visual Communication Desensitization (VCD). Many forensic interview protocols are structured or semi-structured, meaning they are standardized with practitioners following specific guidelines. This standardization facilitates psychometric evaluation, which allows for the testing of the reliability, validity, and cultural tailoring of the tools to different groups of people. Psychometric evaluations also allow for the collection of data to understand if the protocols actually improve interview quality (Hunley, O’Donohue, 2022). The CI is the most well-established and studied technique, while the FETI and VCD are more recently developed and have not undergone the same degree of empirical scrutiny.

The Cognitive Interview

The Cognitive Interview (CI) is one of the most well-established and studied interview protocols. It was developed in the 1980s, for adult and child witnesses and victims of trauma and has been revised over the years, with an “Enhanced Cognitive Interview” developed in 1992, and other modified versions available for different population groups. The CI is used by police to maximize the retrieval of information about a crime using memory retrieval and communications techniques (Memon et al., 2010). Underpinning the CI technique is a recognition of the limited mental resources of victims or witnesses of traumatic events. The goal is to improve the dynamics between the interviewer and interviewee through the building of rapport and allowing multiple and varied ways for an interviewee to recall memories, known as “cognitive mnemonics” (FBI, 2016; Hunley and O’Donohue 2022). The entire process is centred on the interviewee, allowing them to control the flow of information, while the interviewer acts as a facilitator. There are several phases in a cognitive interview (Geiselman et al., 1984):

  1. Establish rapport and describe the interview process
    The interviewer begins by establishing rapport and describing the interview process to the interviewee. The interview process is centered on the interviewee as they control the flow of information and describe the events in their own words.
  2. Open ended questions and active listening
    The second stage of a cognitive interview involves the interviewer asking open ended questions while actively listening without interrupting the interviewee.
  3. Context reinstatement
    Following the open-ended questions, the interviewer uses a method referred to as “context reinstatement”, which involves the interviewee recalling the event using their five senses. This allows for more detailed information about the incident and can produce information that the interviewee may not have thought was important to share during the interview.
  4. Free narrative
    Following the context reinstatement phase, the interviewee provides a free narrative of the incident in whatever order they choose. This means that the free narrative may not be in chronological order. The interviewer reminds the victim of the importance of providing a detailed account by reporting everything they can recall, even if it is partial or incomplete.
  5. Final stages of the interview
    The interviewer may use memory retrieval techniques or cues to prompt the interviewee to access different aspects of the event. For example, the interviewee may be instructed to recall the event from someone else’s perspective, or in reverse chronological order.

The CI was initially developed to enhance witness memory, which means that most of the formal validation testing has only examined the CI’s ability to increase the amount and quality of witness recollection. Evidence has shown the technique obtains the largest amount of accurate information compared to other interviewing protocols (Air Force Report to Congress, 2015). While the CI is widely used and has been shown empirically to be beneficial in comparison to other protocols, Hunley and O’Donohue (2022) noted a few critiques of the approach. Notably, some studies have found that adherence to the CI protocol in real investigations (i.e., not under test conditions) can be poor, with the rapport building phase being shown to be the most likely to be consistently implemented. Also, some have suggested that the CI does not meet the interview objectives of not harming the interviewee and retaining them in the criminal justice process. For example, the approach may unnecessarily increase interview length and complexity in cases where victims are able to provide coherent and comprehensive accounts without the use of the memory mnemonics. In some cases, the level of detail elicited has been reported by prosecutors to potentially fatigue complainants and cause unnecessary confusion. The CI also does not specifically address potential medical, safety or psychological needs of interviewees (Westera, Powell, and Zajac 2023, Hunley and O’Donohue 2022, Hohl and Conway, 2017).

Forensic Experiential Trauma Interview (FETI)

The Forensic Experiential Trauma Interview (FETI) is a newer technique used for forensic interviewing, first developed by Russell Strand, the former head of the Behavioral Sciences Education and Training Division of the United States Army Military Police School (Buckley 2014). FETI techniques aim to reduce inaccuracy of information obtained from trauma victims, considering the impact of stress and trauma on the memory process, and focusing on the sensory aspects of the traumatic experience to better access memories. Proponents of FETI have suggested that it yields significantly more information than traditional techniques, in particular information that allows for a better understanding of the impact of the traumatic experience on the victim (Buckley 2014). FETI does not attempt to answer a predetermined list of questions the interviewer deems important, rather, the goal is to obtain information that the participant is able to tell the interviewer. The FETI process begins with the interviewer expressing sympathy and concern to the complainant as an attempt to provide physical and psychological safety during the interview.

The FETI training describes eight interviewing phases:

  1. Rapport building: the Interviewer acknowledges the victim’s trauma and/or pain;
  2. Ask the victim/witness what they are able to remember about their experience;
  3. Ask the victim/witness about their thought process at particular points during their experience;
  4. Ask about sensory memories: such as sounds, sights, smells, and feelings before, during, and after the incident;
  5. Ask the victim/witness how this experience affected them physically and emotionally;
  6. Ask the victim/witness what the most difficult part of the experience was for them and;
  7. The interviewer inquires if there is anything that the interviewee cannot forget about their experience.
  8. Clarify other information and details.

FETI methodology is used by some law enforcement, victim services and other agencies, with frequent formal trainings held in both Canada and the United States (Strand, 2017). However, there are no published studies that assess any psychometric properties of this protocol, and claims about its effectiveness are largely based on anecdotes and testimonials. A 2015 U.S. Air Force report on the use of FETI for criminal investigations identified several concerns with the technique. Specifically, they found that FETI lacked a sound evidence base, and relied on some outdated concepts in the scientific research on trauma, memory, and neurobiology (Air Force Report to Congress, 2015). Hunley and O’Donohue (2022) highlight concerns about the popularization of the “neurobiology of trauma” in the forensic interview literature, suggesting it could be at best not necessary, but potentially harmful. Specifically, interview protocols that focus on neurobiological impacts may lead to overgeneralizations about the extent to which victims of sexual assault experience trauma or develop post-traumatic stress disorder (PTSD), and assuming homogeneity of neurobiological reactions to trauma can lead to bias that may impact the quality of the forensic interview (Hunley and O’Donohue 2022). Other critiques of FETI have highlighted the interviewer bias that is introduced when the starting point of the interview is to acknowledge the interviewee’s trauma. This presumes that an assault has occurred before the interviewee has even shared details of the incident (Hunley and O’Donohue 2022; McElroy 2018).

Visual Communication Desensitization

A less commonly used forensic interviewing technique is the Visual Communication Desensitization (VCD) interview procedure. This type of forensic interview involves a two-part cognitive behavioural approach that is designed to gather accurate amounts of information quickly, while reducing distress from the interview process. The interviewer maintains sensitivity to the interviewee’s distress level throughout the interview and asks only open questions to elicit information. The VCD was developed considering the impact of PTSD and trauma on memory and recall (Castelfranc-Allen and Hope, 2018).
The VCD interview protocol has two key phases:

  1. The “narrative graph” information gathering

    The narrative graph component involves providing the interviewee with a graph-like form. The vertical axis of this graph is labelled “client sense of distress” and is scaled from 0-100. The horizontal axis of the graph is labelled “client directed timeline.” During the first phase of a VCD interview, the interviewee is asked to think back to the traumatic events that occurred and use a pencil to draw a line on the narrative graph which will fluctuate according to the sense of distress during various parts of recalling the traumatic event.

    The interviewee may talk about the remembered events as they draw the chart or remain silent, and they may stop this phase at any point but are encouraged to get to the end of the traumatic events. If the interviewee chooses to verbally discuss parts of the traumatic event, they are encouraged to keep their pencil on the same place that this event occurred on the graph and mark a short vertical line for a “pause point.” The interviewee can write words for different parts of the traumatic experience. If the interviewee is silent or inaudible while recalling a part of the traumatic event, the interviewer marks the graph with a “harsh point” and uses only open-ended questions to inquire what the interviewee is recalling. The words or phrases provided by the interviewee are recorded either directly on the graph or on a separate sheet of paper.

  2. Dove-tailed therapeutic

    The information provided in the narrative graphs forms the basis for phase two of the VCD, the therapeutic process. During this phase, the levels of distress on the graph are divided into equal bands from 0 to 100, with the most distressful events falling within 90 to 100 range and the least between 0 to 10. The interviewee is then taken through a systemic desensitization process, including physical relaxation and cognitive behavioral therapy techniques. The interviewee or interviewer determines when it is appropriate to end each session. Sessions are related using a new blank graph to try to reach the end of the remembered events from the traumatic experience.

The VCD protocol was developed as a response to an ongoing issue of contamination of trauma reports in cases where time-confused trauma victims were repeatedly questioned, sometimes using leading questions, and narratives in reports would differ making it challenging to distinguish the real facts and evidence of the event (Castelfranc-Allen and Hope, 2018). While there is limited empirical research examining the effectiveness of the VCD, there is one study with mock witnesses of a crime to assess its validity. The study did not find significant differences in the number of correct or incorrect details found compared to a free-recall interview (Castelfranc-Allen and Hope 2018; Hunley and O’Donohue 2022).