Definition
Eyewitness testimony is evidence given in court by a person who perceived events relevant to the case — usually identification of a suspect or recall of what happened. For most of legal history it was treated as one of the strongest forms of evidence; modern memory research has shown this confidence is misplaced.
Memory does not work like a recording. Perception is selective, encoding is shaped by attention and stress, storage decays unevenly, and retrieval is reconstructive — each recollection rebuilds the memory using current knowledge, expectations, and external suggestion. Eyewitness identifications have been the leading single cause of wrongful convictions later overturned by DNA evidence.
Why it matters
Where it shows up
Psychology has reshaped police practice in several jurisdictions: standardised line-up procedures, the Cognitive Interview (a witness-led recall method), and judicial instructions warning jurors about the limits of identification evidence. It has also reshaped admissibility — some courts now require expert testimony on memory before identifying evidence can be heard.