Detecting deception : does the cognitive interview impair discrimination with CBCA criteria in elderly witnesses?

The accuracy of an eyewitness statement depends on the interviewing method used. Therefore, empirically tested interviewing techniques have been developed, in particular for vulnerable witnesses. Sometimes witnesses may not tell the truth based on personally experienced events but give testimony about events they have only heard about, thus lying about the event. In this experiment, 80 witnesses over 60 years old either saw a film or heard an audiotaped summary. They were interviewed either with a standard interview (SI) or an Enhanced Cognitive Interview (ECI). The ECI led to an increase in the amount of information gained without jeopardizing its accuracy compared to the SI. Trained coders evaluated transcripts of the interviews with Criteria-Based Content Analysis and judged the truthfulness of each account. Some differences in CBCA criteria were in the expected direction, others opposite to expectation, thus prohibiting the use of a summary score. Accounts from the SI group (80%) were judged correctly significantly more often than accounts from the ECI group (40%). Only 15% of the lies in the ECI group were judged correctly vs. 80% in the SI group. Findings are discussed regarding the importance of testing interview techniques with respect to their potential to detect deception