After a crime has occurred, one of the most pressing objectives for investigators is to identify and interview any eyewitness that can provide information about the crime. Depending on his or her training, the investigative interviewer will use (to varying degrees) mostly yes/no questions, some cued and multiple-choice questions, with few open-ended questions. When the witness cannot generate any more details about the crime, one assumes the eyewitness’ memory for the critical event has been exhausted. However, given what we know about memory, is this a safe assumption? In line with the extant literature on human cognition, if one assumes (a) an eyewitness has more available memories of the crime than he or she has accessible and (b) only explicit probes have been used to elicit information, then one can argue this eyewitness may still be able to provide additional information via implicit memory tests. In accordance with these notions, the present study had two goals: demonstrate that (1) eyewitnesses can reveal memory implicitly for a detail-rich event and (2) particularly for brief crimes, eyewitnesses can reveal memory for event details implicitly that were inaccessible when probed for explicitly. Undergraduates (N = 227) participated in a psychological experiment in exchange for research credit. Participants were presented with one of three stimulus videos (brief crime vs. long crime vs. irrelevant video). Then, participants either completed a series of implicit memory tasks or worked on a puzzle for 5 minutes. Lastly, participants were interviewed explicitly about the previous video via free recall and recognition tasks. Findings indicated that participants who viewed the brief crime provided significantly more crime-related details implicitly than those who viewed the long crime. The data also showed participants who viewed the long crime provided marginally more accurate details during free recall than participants who viewed the brief crime. Furthermore, participants who completed the implicit memory tasks provided significantly less accurate information during the explicit interview than participants who were not given implicit memory tasks. This study was the first to investigate implicit memory for eyewitnesses of a crime. To determine its applied value, additional empirical work is required.

Gathering evidence from young and vulnerable witnesses requires special care, and subjecting them to the traditional adversarial form of examination and cross-examination – often characterized by overly leading, complex, and confusing questioning – has come under increased scrutiny. The present program of research was designed to investigate: 1) four features of lawyers’ questioning techniques (question type [Chapter 1], linguistic complexity [Chapter 2], question repetition [Chapter 3], and question content [Chapter 4]), 2) how these parameters affected children’s responses (including an in-depth analysis of children’s propensity to express uncertainty [Chapter 5]), and 3) whether the children’s ages affected the ways they were questioned or how they responded. The sample of court transcripts was drawn from 36 trials involving 56 children aged 5 to 17 years old who testified about alleged sexual abuse in Scotland between 2009 and 2014. Analyses showed that a large proportion of the questions posed to children by lawyers were suggestive questions that implied expected responses or introduced undisclosed information. Questions were overly complex linguistically, heavily repetitious, and focused to a large extent on peripheral elements of the allegations. In response, children acquiesced to suggestions most of the time and expressed uncertainty less than might be expected, given the nature of the questioning. Overall, both prosecutors and defense lawyers were insensitive to the capacities of children of different ages. The way children are questioned in court can have negative influences on the quality of the evidence obtained, regardless of the lawyers’ roles or the children’s ages. It is suggested that, in order for trials to be fair, evidence needs to be elicited in accordance with research-informed best-practice guidelines. More advanced training, the use of intermediaries, and the Barnahus model are discussed as potential ways to support the implementation of best-practice questioning strategies.

To stem the spread of infectious diseases, epidemiologists use contact tracing interviews to identify individuals who may need treatment or, if indicated, quarantine or isolation. Given the high stakes, the most exhaustive list of potentially infected contacts must be reported. However, standard contact tracing procedures may fail to extract the most complete report possible from sick individuals. One of the most reliable methods for maximizing recall is the Cognitive Interview (CI). The CI uses several techniques grounded in psychological theory and was expected to increase the number of contacts listed during contact tracing interviewing compared to a standard contact tracing interview. In Study One, participants imagined they were infected with meningococcal meningitis, and reported every person with whom they had physical contact, shared saliva, or lived with over the previous three days (i.e., at a high risk for developing meningococcal meningitis). Participants were interviewed with either a CI or a standard interview. Results suggested that the CI generated 35% more total contacts listed, however, when examining only the contacts listed who would be at a high risk of meningococcal meningitis there was no significant difference between the CI and the standard interview. Study Two followed the same procedure as that in Study One, but added a manipulation of cognitive resources intended to model impairment experienced by individuals who are interviewed while suffering from acute illness. Participants completed (or did not complete) a working memory impairment task (pressed a spacebar on a keyboard every time 7 seconds passed) while reporting their physical contacts during either a CI or a standard interview. Results clearly demonstrated a superiority of the CI in generating both more total contacts and more contacts at a risk of meningococcal meningitis than the standard interview. However, when the working memory impairment task was completed, the CI generated no more contacts than the standard interview. Findings have serious implications for contact tracing interviewing for infectious diseases such as Ebola and Zika. In light of the findings, we recommend the CI be considered as an alternative to the typical contact tracing interview, particularly if the interviewee is not cognitively impaired.

The Self-Administered Interview© (SAI©) is an eyewitness interviewing tool designed to help protect eyewitness memory and elicit a comprehensive initial statement (Gabbert, Hope, & Fisher, 2009). Early research shows promising results in general adult samples. Whether the SAI© is an effective tool for older adult witnesses has not yet been fully addressed. Older adults will become increasingly important as a witness population in the future, yet perform worse compared to young adults. Some attempts have been made to aid older adult witnesses, but an easy-to-apply and effective method is yet to be introduced. This dissertation presents an overview of current knowledge on eyewitnesses and provides a theoretical basis for the empirical chapters. It further presents results of a systematic review and several meta-analyses on the effectiveness of the SAI© as a means to enhance eyewitness testimony. The meta-analyses cover 38 experimental comparisons from 22 empirical studies representing 1712 interviewees. Results indicate a strong benefit of the SAI both immediately after the witnessed crime (d = 1.20) and in a delayed recall (d = 0.92 compared to no initial recall) after one to three weeks. The third large chapter of this dissertation presents the results of an experiment that investigated the effectiveness of the SAI© for older witnesses’ testimony, suggestibility and lineup performance. 144 participants, half of which were 60 years or older and half aged 18-30 years, took part in two sessions. In the first session, they were shown a film of a staged crime and either filled in the SAI©, gave a written free recall or no initial recall. In the second session after one week they were then asked to give a free recall of what they remembered, answer questions including suggestive questions, and also to identify the perpetrator from the film from a 6-person simultaneous photo lineup. Results confirm the classic SAI© effect for young adults, show a small beneficial effect for older adults and also indicate a beneficial effect for lineup performance for the first time.

Most investigative interviewing protocols, including the National Institute of Justice’s 1999 guidelines on collecting eyewitness evidence, recommend building rapport with cooperative witnesses to increase the quality and quantity of details obtained at recall. To date, only three published articles have empirically addressed the effects of rapport-building on adult witness memory, and all suggest an increase in witness accuracy under certain conditions. However, to our knowledge no research has addressed the importance of the investigator when building rapport and whether rapport can increase witness susceptibility to suggestive-leading questions – the aim of the current research. Specifically, this project examined the effects of change in interviewer between rapport and retrieval, and the effects of interviewer suggestion after rapport eyewitness memory accuracy. Participant witnesses (N=198) viewed a videotaped mock convenience store robbery followed by rapport-building or a standard police interview about non-crime related details (rapport manipulation). One week later all participants were interviewed about the mock crime they witnessed either by the same or a different interviewer (interviewer manipulation). All witnesses were interviewed about the mock crime using open-ended questions about the event, witnesses, suspect, and location followed by a series of specific suggestive questions containing both correct- and incorrect-leading information about the crime. Videotaped and transcribed witness reports were scored for accurate and false information by two independent raters. Findings indicated that, contrary to all hypotheses, neither rapport-building on day 1 nor change in interviewer on day 2 (one week later) manipulations resulted in significant effects on the primary accuracy dependent measures on day 2, including open-ended and suggestive-leading questions. The present study was the first to investigate the effect of rapport-building on eyewitness recall after a delay, whether changing interviewers across the investigation impacts recall, and whether rapport can act as a safeguard by inoculating witnesses against investigator-provided misinformation. These null findings further suggest that future research should disentangle the specific conditions under which rapport-building facilitates witness recall need to be disentangled in future research.

Contrary to interviewing guidelines, a considerable portion of witness interviews are not recorded. Investigators’ memory, their interview notes, and any subsequent interview reports therefore become important pieces of evidence; the accuracy of interviewers’ memory or such reports is therefore of crucial importance when interviewers testify in court regarding witness interviews. A detailed recollection of the actual exchange during such interviews and how information was elicited from the witness will allow for a better assessment of statement veracity in court. Two studies were designed to examine interviewers’ memory for a prior witness interview. Study One varied interviewer note-taking and type of subsequent interview report written by interviewers by including a sample of undergraduates and implementing a two-week delay between interview and recall. Study Two varied levels of interviewing experience in addition to report type and note-taking by comparing experienced police interviewers to a student sample. Participants interviewed a mock witness about a crime, while taking notes or not, and wrote an interview report two weeks later (Study One) or immediately after (Study Two). Interview reports were written either in a summarized format, which asked interviewers for a summary of everything that occurred during the interview, or verbatim format, which asked interviewers to record in transcript format the questions they asked and the witness’s responses. Interviews were videotaped and transcribed. Transcriptions were compared to interview reports to score for accuracy and omission of interview content. Results from both studies indicate that much interview information is lost between interview and report especially after a two-week delay. The majority of information reported by interviewers is accurate, although even interviewers who recalled information immediately after still reported a troubling amount of inaccurate information. Note-taking was found to increase accuracy and completeness of interviewer reports especially after a two week delay. Report type only influenced recall of interviewer questions. Experienced police interviewers were not any better at recalling a prior witness interview than student interviewers. Results emphasize the need to record witness interviews to allow for more accurate and complete interview reconstruction by interviewers, even if interview notes are available.

À ce jour, peu est encore connu sur les facteurs individuels, délictuels et situationnels permettant de prédire l’aveu d’agresseurs sexuels. Ceci pose particulièrement problème sachant que leur taux d’aveu est plus faible que les auteurs d’autres crimes et que cet aveu constitue souvent la seule preuve de culpabilité à leur égard. Une étude de cas-témoins a été privilégiée afin (1) d’identifier les facteurs associés à l’aveu et (2) d’en établir un modèle multivarié permettant de mieux comprendre la passation à l’aveu d’agresseurs sexuels en contexte d’entrevue d’enquête. Soixante-dix-huit hommes adultes ayant été reconnu coupables d’agression sexuelle ont été recrutés au Centre régional de réception, un établissement correctionnel fédéral situé au Québec (Canada), et divisés en deux groupes (c.-à-d. confesseurs vs non-confesseurs). Les résultats obtenus sont les premiers à mettre en valeur l’apport que peuvent avoir les facteurs situationnels relatifs à l’enquête (p. ex. type de preuve, consultation d’un avocat, cadre physique de l’interrogatoire) dans l’aveu d’agresseurs sexuels spécifiquement. Les résultats appuient également le fait qu'une approche intégrée de l'aveu, c’est-à-dire qui tiendrait à la fois compte des facteurs individuels, délictuels et situationnels, est à favoriser afin de mieux comprendre ce qui pousse les auteurs d'agressions sexuelles à avouer en contexte d'entrevue d'enquête. Les modèles de régression obtenus et leurs facteurs explicatifs seront discutés en lien avec leur incidence sur les pratiques policières en contexte d’entrevue d’enquête. / Much is still yet unknown of individual, offense and situational factors allowing to predict sexual offenders’ confession to their crime. This is particularly worrying given that sexual offenders’ confession rate is lower compared to other type of offenders and that their confession is often the sole evidence available. A case-control study was chosen to (1) identify factors associated to confession, and (2) elaborate a multivariate model helping to better understand sexual offenders’ decision to confess during an investigative interview. Seventy-eight adult males convicted of sexual aggression were recruited at the Regional Reception Centre, a federal correctional facility located in Quebec (Canada), and divided into two groups (i.e. confessors vs non-confessors). The obtained results were the first to highlight the contribution of situational factors pertaining to the investigation (e.g. type of evidence, consultation of a lawyer, setting of the interrogation room) in sex offenders’ confession specifically. The results also support an integrative approach to confession that would take into account individual, offense and situational factors in order to better understand what makes sexual offenders confess in an investigative interview. The regression models and the predictor variables within them are further discussed in relation to their implications for police practices in the interrogation room.

This research investigates the communication abilities of children who are exposed to criminal investigations because a crime was committed against them or they have witnessed a crime happening to another person. The study also determines how crime detectives can maximise their efforts in obtaining evidence from such children with the help of an interview as a technique to elicit information. The aim of the research was to understand the behaviour of children, so that more effective investigative interviews can be undertaken with child victims. The researcher wanted to identify the communication challenges associated with obtaining information from child victims and possible ways to overcome such challenges. It was found that the developmental stages of children, the manner in which interviewers/investigators conduct themselves during child interviews and the amount of knowledge possessed by interviewers to elicit information in a legally defensible manner are central to child victim interviews. / Criminology and Security Science / M. Tech. (Forensic Investigation)

This research investigates the communication abilities of children who are exposed to criminal investigations because a crime was committed against them or they have witnessed a crime happening to another person. The study also determines how crime detectives can maximise their efforts in obtaining evidence from such children with the help of an interview as a technique to elicit information. The aim of the research was to understand the behaviour of children, so that more effective investigative interviews can be undertaken with child victims. The researcher wanted to identify the communication challenges associated with obtaining information from child victims and possible ways to overcome such challenges. It was found that the developmental stages of children, the manner in which interviewers/investigators conduct themselves during child interviews and the amount of knowledge possessed by interviewers to elicit information in a legally defensible manner are central to child victim interviews. / Criminology and Security Science / M. Tech. (Forensic Investigation)