In eyewitness identification, in criminal law, evidence is received from a witness "who has actually seen an event and can so testify in court".

The Innocence Project states that "Eyewitness misidentification is the single greatest cause of wrongful convictions nationwide, playing a role in more than 75% of convictions overturned through DNA testing." This non-profit organization uses DNA evidence to reopen criminal convictions that were made before DNA testing was available as a tool in criminal investigations.

Even before DNA testing revealed wrongful convictions based on eyewitness identifications, courts recognized and discussed the limits of eyewitness testimony. The late U.S. Supreme Court Justice William J. Brennan, Jr. observed in 1980 that "At least since United States v Wade, 388 U.S. 218 (1967), the Court has recognized the inherently suspect qualities of eyewitness identification evidence, and described the evidence as "notoriously unreliable", while noting that juries were highly receptive to it. Similarly, in the United Kingdom, the Criminal Law Review Committee, writing in 1971, stated that cases of mistaken identification "constitute by far the greatest cause of actual or possible wrong convictions".

Historically, Brennan said that "All the evidence points rather strikingly to the conclusion that there is almost nothing more convincing  than a live human being who takes the stand, points a finger at the defendant, and says 'That's the one!'" Another commentator observed that the eyewitness identification of a person as a perpetrator was persuasive to jurors even when "far outweighed by evidence of innocence."