A showup identification is the presentation of a single suspect to an eyewitness. I used a simulated theft paradigm and subsequent showup identification to examine the effects of stolen property, suspects’ verbal behaviour, and target-presence on eyewitness identification performance. I used a 2 (suspect: innocent, guilty) X 2 (stolen property: present, hidden) X 3 (verbal behaviour: denial with explanation, denial, silence) between-subjects factorial design. Binary logistic regression analysis indicated that both the target and stolen property, independently, and significantly predicted the accuracy of identification decisions. Surprisingly, the presence of stolen property facilitated more accurate identification decisions from eyewitnesses. / UOIT

published_or_final_version / Psychology / Doctoral / Doctor of Philosophy

During a crime event, witnesses may have to judge the veracity of a suspect. I hypothesized that, because performing this task is cognitively demanding, (a) it would impair subsequent memory for details about the suspect and (b) judging veracity while motivated to do so as accurately as possible would exaggerate this effect. These predictions were supported. Additionally, witnesses who judged veracity reported increased certainty about the accuracy of their description and message and their identification of the suspect compared to control witnesses, and they also said they had a better view of the suspect and paid more attention to him. Motivation further inflated some of these testimony-relevant judgments. Moreover, compared to control witnesses, motivated witnesses who judged veracity reported a greater willingness to testify and a clearer image of the suspect in their memory. / Department of Psychological Science

Psychologists, legal practitioners and scholars share the knowledge that honest eyewitnesses can err in their attempts to identify the perpetrator of a crime. This thesis reports an experimental investigation of the extent to which expert evidence and judicial instruction can improve juror ability to discriminate between accurate and inaccurate identifications. Special attention is also paid to the logic of inferences which have been made by psychologists regarding the efficacy of expert evidence, and compares methodologies adopting direct measures of participant Sensitivity to Eyewitness Accuracy (SEA) with those that can only indirectly assess this construct. Study 1 surveys the knowledge and opinions of legal professionals regarding eyewitness identification issues (n = 35), showing that respondents expressed doubts that judicial instructions would exert an effect equivalent to that of eyewitness expert evidence. Accordingly, Experiments 1 to 4 (Experiment 1, n = 104; Experiment 2, n = 238; Experiment 3, n = 228; Experiment 4, n = 297) were conducted to directly assess the relative impacts of judicial instruction and expert evidence on participant juror SEA. The methodology utilised in these investigations incorporated the testimony of real eyewitnesses to a staged crime scenario in order to assess the impact of instruction on juror ability to discriminate between known accurate and known inaccurate eyewitnesses. Overall, little evidence was found to support the notion that expert evidence is more effective than judicial instruction, as no significant association was identified between instruction type and SEA. This result was found to hold irrespective of the objective quality of the expert?s testimony (accurate or erroneous). In light of the results from Experiments 1 to 4, Experiment 5 was designed to investigate why the experts were not able to improve the discrimination accuracy of the jurors. This study focused on the extent to which participants of varying levels of expertise could correctly classify eyewitness accuracy. The results of Experiment 5 (n = 145) suggest that experts were no better able to discriminate between accurate and inaccurate eyewitnesses than novice laypeople. Overall, the evidence reported in this thesis raises serious questions regarding the utility of eyewitness expertise in the completion of eyewitness discrimination tasks.

Thesis (Ph.D.)--University of Wollongong, 2004. / Volume 2 contains amendments to the thesis. Typescript. Includes bibliographical references: leaf 223-242.

Thesis (Ph. D.)--University of Texas at El Paso, 2008. / Title from title screen. Vita. CD-ROM. Includes bibliographical references. Also available online.

Thesis (M. A.)--Roger Williams University, 2009. / Title from title page screen (viewed on Oct. 29, 2009) Includes bibliographical references.

Thesis (M.Sc.)--Acadia University, 2006. / Includes bibliographical references (leaves 158-166). Also available on the Internet via the World Wide Web.

Thesis (M.A.)--University of Texas at El Paso, 2009. / Title from title screen. Vita. CD-ROM. Includes bibliographical references. Also available online.

This thesis presents research designed to explore the role of physiological and psychological factors in mediating the effects of victimisation upon eyewitness memory. A tripartite model of arousal and memory is proposed encompassing physiological, psychological and motivational mechanisms. In order to investigate the potential role of these mechanisms, three laboratory based studies and one archival study are presented. The results of the laboratory studies suggest that physiological arousal may not influence eyewitness memory. In contrast, whilst direct support for an influence of psychological arousal is not provided, the possibility that psychological arousal may be an important factor cannot readily be dismissed. From a methodological perspective, contrary to existing laboratory-based research concerning visually-induced arousal, the results of the laboratory studies suggest that personal involvement may be an important factor influencing memory. Furthermore, the third laboratory study found that, differences in memory for emotional and neutral material may be a function of inherent differences between the material rather than an influence of arousal. Finally, in order to compare and contrast laboratory based research with the performance of real witnesses, a field based study utilising closed-circuit television to assess eyewitness accuracy for action details was conducted. In line with Studies One and Two, victims and bystanders were not found to differ in their memory performance. This study provides direct support for existing field and archival research suggesting that real victims and bystanders tend to be highly accurate in their eyewitness accounts. Taken together, the results of the research presented in this thesis suggest that whilst physiological arousal may not be an important factor influencing eyewitness memory, psychological and motivational influences may be important when witnesses are personally involved with the target incident.