我国刑事见证制度的价值及完善

刑事见证制度是保证国家公诉的透明度和公信力之关键,具有独立的程序价值。我国刑事诉讼法律规范在见证制度方面存在诸多不足之处,这对司法机关依法规范侦查行为、统一证据标准造成混乱,也对我国的人权保障形成制度障碍。对此,我国刑事诉讼法应当从见证人的选取、见证人的权利和义务、见证制度的违反后果等方面统一见证制度的程序和实体标准,为证据的可信度提供制度保障。     

Can training improve eyewitness identification? The effect of internal feature focus on memory for faces

Evidence suggests that individuals rely on external features such as hair and face shape when processing and recognising unfamiliar faces. This is problematic in a forensic setting because hairstyle can be changed easily. In two studies we examined whether training individuals to focus more on the stable, internal features of the face (e.g. eyes, nose and mouth) and hence less on the changeable external features would improve identification accuracy. In Study 1, participants were instructed to focus on: (1) internal features, (2) external features, or (3) both internal and external features. Participants’ eye movements were monitored while they studied target faces, which they later tried to identify from an array that included the target with a changed appearance. In Study 2, participants were instructed to focus on: (1) internal features, (2) external features, or (3) given no instructions. Participants were required to identify target faces from line-ups, where they were presented either unchanged or with an altered hairstyle. Results suggested that training individuals to attend to internal features of unfamiliar faces may improve identification accuracy in the common situation where external features have changed between presentation and identification. However, internal feature focus may decrease identification accuracy when external features are unchanged.     

Inconsistencies across repeated eyewitness interviews: supportive negative feedback can make witnesses change their memory reports

Past work shows that direct negative feedback and suggestive questioning can lead eyewitnesses to change their memory reports. Applying Gudjonsson’s [2003. The psychology of interrogations and confessions: A handbook. West Sussex: Wiley] model of interrogative suggestibility to interviews with witnesses, the present two experiments examined how indirect negative feedback delivered in a supportive manner from an interviewer can make witnesses change what they report they remember experiencing. After viewing a video of a crime, participants were interviewed twice, with either supportive negative feedback (i.e. with the interviewer sympathetically suggesting why many people’s memory may be inaccurate) or neutral feedback between the two rounds of questions. Results showed that people given supportive negative feedback changed significantly more of their responses than those given neutral feedback. Lower confidence ratings were associated with greater response change, but overall, despite having changed more responses, people given supportive negative feedback did not have reduced confidence or perceived accuracy. Type of feedback did not impact accuracy, and accuracy was not systematically related to confidence or perceived accuracy. Given the role that eyewitness reports play in the criminal justice system, better understanding factors that impact consistency and reliability is vital.     

Interviewing Witnesses: The Effect of Forced Confabulation on Event Memory

After viewing a crime video, participants answered 16 answerable and 6 unanswerable questions. Those in the "voluntary guess" condition had a "don't know" response option; those in the "forced guess" condition did not. One week later the same questions were answered with a "don't know" option. In both experiments, information generated from forced confabulation was less likely remembered than information voluntarily self-generated. Further, when the same answer was given to an unanswerable question both times, the confidence expressed in the answer increased over time in both the forced and the voluntary guess conditions. Pressing eyewitnesses to answer questions, especially questions repeated thrice (Experiment 2), may not be an effective practice because it reliably increases intrusion errors but not correct recall.     

Public Eyewitness Confidence Can Be Influenced by the Presence of Other Witnesses

Four experiments were conducted to examine whether witnesses' public confidence ratings differ from their private ratings when there are social pressures to use confidence as an impression-management tool. In all four experiments, participants answered questions about a source event (a series of faces in the first three experiments and a simulated crime scene in the fourth). Half of the responses and confidence ratings were given privately and anonymously, and half were given publicly in front of one or more mock jurors. Two central findings emerged from the results. First, public confidence differed from private confidence only when there was more than one witness; when there were no other witnesses, public and private confidence were the same. Second, the direction of the change in public confidence in the multiple-witness settings was influenced by whether or not there was a possibility of being contradicted by the other witnesses. When there was no chance that the participants' responses could be contradicted, they raised their confidence ratings in public; when there was a chance that the other witnesses might contradict them, the participants lowered their public confidence ratings. The results are discussed in terms of self-presentation theory and implications for the legal system.     

Mug Shot Exposure Effects: Does Size Matter?

This research tested whether mug book size moderates mug shot exposure effects. Witnesses to a simulated theft searched either a small, a large, or no mug book, followed by a perpetrator-absent lineup containing a critical foil from the mug book. Contrary to predictions of a transference effect, critical foil lineup identifications did not differ across conditions. To test for a commitment effect, only participants who selected the critical foil in the mug book were considered; there was evidence of a commitment effect in the large mug book condition. Finally, there were more lineup-correct rejections in the large mug book condition; this was explained in terms of the criterion for making mug book choices carrying over to lineup choices.

How Can We Help Witnesses to Remember More? It’s an (Eyes) Open and Shut Case

Five experiments tested the idea that instructing a witness to close their eyes during retrieval might increase retrieval success. In Experiment 1 participants watched a video, before a cued-recall test for which they were either instructed to close their eyes, or received no-instructions. Eye-closure led to an increase in correct cued-recall, with no increase in incorrect responses. Experiments 2-5 sought to test the generality of this effect over variations in study material (video or live interaction), test format (cued- or free-recall) and information modality (visual or auditory details recalled). Overall, eye-closure increased recall of both visual detail and auditory details, with no accompanying increase in recall of false details. Collectively, these data convincingly demonstrate the benefits of eye-closure as an aid to retrieval, and offer insight into why hypnosis, which usually involves eye-closure, may facilitate eyewitness recall.     

Policy Forum: Studying Eyewitness Investigations in the Field

This article considers methodological issues arising from recent efforts to provide field tests of eyewitness identification procedures. We focus in particular on a field study (Mecklenburg 2006) that examined the “double blind, sequential” technique, and consider the implications of an acknowledged methodological confound in the study. We explain why the confound has severe consequences for assessing the real-world implications of this study.     

Regularities in Eyewitness Identification

What do eyewitness identification experiments typically show? We address this question through a meta-analysis of 94 comparisons between target-present and target-absent lineups. The analyses showed that: (a) correct identifications and correct-nonidentifications were uncorrelated, (b) suspect identifications were more diagnostic with respect to the suspect’s guilt or innocence than any other response, (c) nonidentifications were diagnostic of the suspect’s innocence, (d) the diagnosticity of foil identifications depended on lineup composition, and (e) don’t know responses were nondiagnostic with respect to guilt or innocence. Results of diagnosticity analyses for simultaneous and sequential lineups varied for full-sample versus direct-comparison analyses. Diagnosticity patterns also varied as a function of lineup composition. Theoretical, forensic, and legal implications are discussed.