Inaccurate eyewitness testimony is a leading cause of wrongful convictions. As early as 1967, the U.S. Supreme Court recognized this danger, but the tests it promulgated to distinguish reliable from unreliable eyewitness testimony were based largely on surmise. More recently, substantial research has demonstrated that, while significant improvements can be made in the manner in which lineups, photo arrays, and other identification procedures are conducted, inherent limitations of human perception, memory, and psychology raise, in many cases, intractable barriers to accurate eyewitness testimony. Where barriers to accurate eyewitness testimony exist, one response is to sensitize jurors to the limitations of eyewitness identifications, but studies to date have not shown that special jury instructions can accomplish that purpose. Moreover, research on expert testimony has produced mixed results, with some studies showing that it helps jurors discriminate between good and bad eyewitness evidence, and other studies showing that it merely creates overall skepticism.