The case for expert testimony about eyewitness memory.

Eyewitness expert testimony informs a jury about psychological processes and accuracy-related variables in eyewitness testimony. Appropriately chosen testimony is not prejudicial, and it is on sound scientific ground. Eyewitness research has established reliable, applicable findings and demonstrated that jurors have insufficient knowledge of some findings and poorly judge eyewitness accuracy. Studies of trial dynamics and reactions to eyewitnesses suggest a sizable risk of inordinate eyewitness impact, creating sizable risk of conviction on the basis of mistaken identifications. Trial simulations examining eyewitness expert testimony indicate it promotes modest, appropriate increases in skepticism about eyewitnesses, even when the expert gives a general overview of research and admits to limitations. The psychological and legal professions should develop responsible guidelines for use of expert testimony in court.