Witnesses’ Verbal Evaluation of Certainty and Uncertainty During Investigative Interviews: Relationship with Report Accuracy

Abstract

The Enhanced Cognitive Interview (CI) is a widely studied method to gather informative and accurate testimonies. Nevertheless, witnesses still commit errors and it can be very valuable to determine which statements are more likely to be accurate or inaccurate. This study examined whether qualitative confidence judgments could be used to evaluate report accuracy in a time-saving manner. Forty-four participants watched a mock robbery video and were interviewed 48 h later with a revised CI. Participants’ recall was categorized as follows: (1) evaluated with very high confidence (certainties), (2) recalled with low-confidence utterances (uncertainties), or (3) recalled with no confidence markers (regular recall). Certainties were more accurate than uncertainties and regular recall. Uncertainties were less accurate than regular recall; thus, its exclusion raised participants’ report accuracy. Witnesses were capable of qualitatively distinguishing between highly reliable information, fairly reliable information, and less reliable information in a time-saving way. Such a distinction can be important for investigative professionals who do not know what happened during the crime and may want to estimate which information is more likely to be correct.

Appendix

Interview protocol

Full description of the interview protocol according to the interview phase

During phase 1 (preliminary phase), procedures such as greeting, establishing rapport, explaining the instructions and interview purpose to the witness, and asking not to guess were followed. This included the transfer of control instruction: (…) you are the only one who saw the video and have the ability to report all the important information (…) you can tell me what happened in the order you desire and pause whenever you want; as well as the report everything instruction:(…) please tell me everything you remember with as much detail as you can (…) even the details that might seem irrelevant to you are very important to me (…) tell me everything that pops into your mind.

During phase 2 (free report), all participants were asked to recall what they could remember about the video event in any order and pace they desired. They were reminded to report everything they could remember with as much detail as possible, and mental reinstatement of context was applied: (…) Try to remember the day you have watched the video (…) think about how you were feeling that day (…) now picture the crime scene in your mind (…) as clear as possible (…) picture all the sounds (…) all the objects (…) all the persons (..) and now focus on what happened and tell me everything you can remember.

During phase 3 (open-ended questioning), three open-ended questions were asked to each participant about his/her free report (e.g., Please describe the cashier – if the participant previously reported seeing the cashier). Mental imagery instructions were used – e.g., you told me you looked at the cashier when he lifted his arms. Can you please close your eyes …, think about everything you remember concerning him …, his face …, his body…, his voice…, and when you have a full picture of him in your mind, describe everything you can remember about him.

During phase 4 (second recall), participants were asked to report everything they could remember about the video once again: (…) I know it may seem redundant, but it is actually highly important you report one more time what happened on the video (…) report not only new information you might recall but also all the information you have already reported (…). They were encouraged to give this second report and this procedure importance was explained: It is very important you focus as hard as you can and tell me one more time what happened on the video. Participants were asked to use category clustering recall (CCR). This recall strategy consisted of asking participants to organize their recall/speech in information categories (objects, locations, actions, voices, sounds): Please tell me everything you remember but focus in one information category at a time (…). First, tell me everything you remember about the objects that were at the crime scene and describe them one by one (…) Ok, now tell me about the position, or positions, people occupied during the crime (…) Great, now focus on the actions that occurred during the crime (…) Thank you, now focus on what you remember hearing (…) tell me about what people said and lastly focus on any other sounds you might have heard (…).

During phase 5 (third recall), participants were asked to focus one more time on the event and try to report any new detail they could remember. This procedure’s importance was again explained and participants were encouraged to do their best. They were here asked to focus on the event in the reverse order: (…) Please tell me what happened in reverse order (…) Focus on the last episode you remember … then focus on the previous one … and so on (…). What is the last episode you remember?

Phase 6 (summary) is fully described in the article as it also includes important information about the method used to evaluate certainties (i.e., participants’ retrospective evaluations of high confidence).

During the last phase (closure), appreciation for participants’ hard work and cooperation was acknowledged and neutral topics were discussed.