TABLE OF CONTENTS

LIST OF TABLES ………………………………. …………………………………………… iv
LIST OF FIGURES ………………………………. …………………………………………. vi
ACKNOWLEDGMENTS………………………………. …………………………………. vii
ABSTRACT………………………………. …………………………………………………….. viii
CHAPTER 1 INTRODUCTION ……………………………………………………………….. 1
The Use of Showup Procedures in the United States ………………………………….. 2
Case Law Related to Showups …………………………………………………………….. 4
Factors Influencing Eyewitness Identification ……………………………………………. 5
Estimator Variables ……………………………………………………………………………. 5
System Variables ……………………………………………………………………………… 6
Eyewitness Decision-Making ………………………………………………………………….. 6
Decision-Making at Identification ………………………………………………………. 7
Post-Identification Judgments …………………………………………………………….. 9
Victim-Bystander Status and the Frustration-Aggression Hypothesis ……………. 10
Aggression and Eyewitness Decision-Making ……………………………………… 11
Review of Previous Victim-Bystander Research …………………………………………. 14
Hypotheses …………………………………………………………………………………………… 17
CHAPTER 2 METHOD ………………………………………………………………………….. 20
Methods …………………………………………………………………………………………… 20
Materials …………………………………………………………………………………………… 21
Procedure …………………………………………………………………………………………… 26
CHAPTER 3 RESULTS …………………………………………………………………………… 31
Preliminary Analyses ………………………………………………………………………………. 31
Negative Affect ………………………………………………………………………………… 31
Eyewitness Motivation Measures ……………………………………………………….. 32
Primary Analyses …………………………………………………………………………………… 34
Decision-Making at Identification ………………………………………………………. 35
Post-Identification Judgments ……………………………………………………………… 39
Anger as a Mediator of Post-Identification Judgments……………………………. 44
CHAPTER 4 DISCUSSION ……………………………………………………………………… 46
Aggression, Victim-Bystander Status and Eyewitness Decision-Making ………. 47
Culprit Presence and Eyewitness Decision-Making ……………………………………. 55
Limitations …………………………………………………………………………………………… 60
Conclusion ……………………………………………………………………………………………. 63
REFERENCES ……………………………………………………………………………………………. 65
TABLES ……………………………………………………………………………………………… 70
FIGURES ……………………………………………………………………………………………… 88
APPENDIX A DEMOGRAPHICS QUESTIONNAIRE ………………………………… 90
APPENDIX B BOGUS COMMUNICATION TASK ……………………………………. 91
APPENDIX C CULPRIT AND INNOCENT SUSPECT PHOTOGRAPHS …….. 94
APPENDIX D SUSPICION CHECK FORM ……………………………………………….. 95
APPENDIX E BOGUS CAMPUS THEFT REPORT ……………………………………. 96
APPENDIX F SHORTENED PROFILE OF MOOD STATES ………………………. 99
APPENDIX G MANIPULATION CHECKS ……………………………………………….. 100
APPENDIX H DEBRIEFING ……………………………………………………………………… 101
APPENDIX I IRB APPROVAL LETTER …………………………………………………… 102