Eyewitness Memory for Person Identification: Predicting Mugbook Recognition Accuracy According to Person Description Abilities and Subjective Confidence of Witnesses

Mugbook searches are conducted in case a suspect is not known and to assess if a previously convicted person might be recognized as a potential culprit. The goal of the two experiments reported here was to analyze if prior statements and information about the suspect can aid in the evaluation if such a mugbook search is subsequently advised or not. In experiment 1, memory accuracy for person descriptors was tested in order to analyze, which attributes could be chosen to down-scale the mugbook prior to testing. Results showed that age was the most accurate descriptor, followed by ethnicity and height. At the same time self-assessed low subjective accuracy of culprit descriptions by the witness seemed to be divergent to the objective actual performance accuracy. In experiment 2, a mugbook search was conducted after participants viewed a video of a staged crime and gave a description of the culprit. Results showed that accuracy in mugbook searches correlated positively with the total number of person descriptors given by the witness as well as with witness’ description of external facial features. Predictive confidence (i.e., subjective rating of own performance in the subsequent mugbook search), however did not show any relation to the identification accuracy in the actual mugbook search. These results highlight the notion that mugbooks should not be conducted according to the subjective estimation of the witness’ performance but more according to the actual statements and descriptions that the witness can give about the culprit.