When Ecphory Fails: Secondary Processes in Eyewitness Identification

Iowa State University, Ames IA

Investigators

Abstract

Mistaken eyewitness identification from police lineups is the primary cause of the conviction of innocent people. Improvements to lineups developed by psychological scientists have benefitted the legal system. But, further improvements require a better understanding of the role played by secondary processes. Unlike the primary process (recognition memory) secondary processes are slow, effortful, deliberative, verbalizable, and largely insensitive to whether or not the culprit is in the lineup. These secondary processes include inferences, deductions, elimination processes, relative judgments, and other forms of reasoning. Secondary processes are hypothesized to be engaged when the primary process fails and can lead to disastrous affirmative identification decisions. Six experiments (total N=2400) are conducted in which people view a simulated crime and attempt an identification from either a culprit-present or a culprit-removed lineup. Each experiment is carefully designed to induce a failure of recognition in one-half of the conditions so as to study the engagement of secondary processes. Two experiments manipulate failure of the recognition experience at the level of memory acquisition (e.g., giving some of them a poor view of the witnessed event), two experiments manipulate failure of the recognition experience at the level of memory storage (e.g., manipulating the passage of time between viewing and the lineup), and two experiments manipulate the recognition experience at the level of memory retrieval (e.g., a grainy, low-resolution lineup task). The tendency of witnesses in culprit-removed lineup conditions to shift identifications to fillers (rather than making no identification) is predicted to be greatest in the conditions that induce recognition failure. In addition, the verbalizations of participant witnesses are studied to learn more about the nature of the secondary processes that map into these identification errors. The findings can help us develop better lineup procedures and better diagnose when mistaken identifications occur.