Effective interrogation of the eyewitness

Eyewitness reports have been investigated in the psychological laboratory from time to time ever since 1900. Specimen studies from the early period and from the last decade indicate that free reports are consistently more accurate but less complete than reports obtained through specifically directed inquiry. The optimal combination is free report followed by the asking of specific questions. The wording of those questions, however, can have a substantial effect on the answers given. Furthermore, the wording of questions put to a witness can distort the witness's memory for the previously experienced event. These techniques and findings have implications for the study of other “retrieval” techniques such as hypnosis. Although laboratory-type control cannot be expected in practical settings, scientific validation of interrogation methods as practiced can be obtained if recording is complete and accurate, if processes of memory restoration or amplification are studied as they occur in the course of interrogation, and if outcome studies are fully reported, including both successes and failures to gain new information or to substantiate existing information.