Expert Testimony: Memory

An eyewitness testifies from memory about events he or she observed.

We provide expert testimony on the factors that affect the accuracy of memory.

The best circumstances to establish and maintain a good memory for an event are to have perceived it adequately, attended to it at the time, the event/people are familiar, the witness’s memory is protected from new post-event information, the witness reports what he or she saw soon after the event, and the witness was not subjected to misleading or directed questioning.

The negative factors include:

Perception Factors: the witness viewed the crime in poor light, at night, against back lighting, from a great distance, in the fog, or very briefly.

Attention Factors: presence of weapons or gore that narrow attention away from the perpetrator’s features, many people are present, noise, lots of distraction.

Unfamiliarity Factors: perpetrator was a stranger; events were unexpected; cross racial identification was involved.

Post-Event Factors: witness has learned new information after first describing the crime.

Time Factors: long delay between witnessing and reporting, and between reporting and testifying.

Questioning Factors: misleading, leading, biased or pressure questioning of the witness.

In addition to consultation and testimony regarding these factors, we provide Content Analyses of changes in testimony as a result of repeated, leading, misleading, presupposition, biased or linguistically pressured questions; interpretation of meaning of documents or spoken language.

CLICK HERE to view our complete review of the factors that affect the accuracy of memory: Ralph Haber and Lyn Haber (2000). Experiencing, Remembering and Reporting Events. The Cognitive Psychology of Eyewitness Testimony. Psychology, Public Policy and Law, Vol. 6, pp. 1057-1097.