Eyewitness testimony refers to verbal state­ ments from people regardi ng what they observed and can purportedly remember that would be relevant to issues of proof at a criminal or civil trial. Such state­ ments constitute a common form of evidence at trials. Eyewitness identification is a specific type of eyewit­ ness testimony in which an eyewitness claims to rec­ ognize a specific person as one who committed a par­ ticular action. In cases where the eyewitness knew the suspect before the crime, issues of the reliability of memory are usually not contested. In cases where the perpetrator of the crime was a stranger to the eyewit­ ness, however, the reliability of the identification is often at issue. Researchers in various areas of experi­ mental psychology, especially cognitive and social psychology, have been conducting scientific studies of eyewitness testimony since the early 1900s, but most of the systematic research has occurred only since the mid- to late 1970s. There now exists a large body of published experimental research showing that eyewit­ ness testimony evidence can be highly unreliable under certain conditions. In recent years, wrongful convictions of innocent people have been discovered through post-conviction DNA testing, and these cases show that more than 80 percent of these innocent people were convicted using mistaken eyewitness identification evidence. These DNA exoneration cases, along with previous analyses of wrongful convictions, poi nt to mistaken eyewitness testimony as the primary cause of the conviction of innocent people.