Although eyewitness is an important resource to consider in investigation, it is not always possible to get an accurate, objective description of an event from an eyewitness. According to Costanzo and Krauss (2012), “eyewitness certainty is an unreliable indicator of accuracy” (p. 143). The inaccuracy of eyewitness information may be caused by errors of attribution and social cognition process.
An eyewitness attributes what happened in an event and stores the information into the memory. Upon request, the eyewitness may recall the information from memory and describe the event accordingly. Errors are likely to occur in this cognitive process. Psychological studies have shown that this process involves three stages: encoding, storage, and retrieval, and “errors in memory can occur at each stage of the process” Costanzo & Krauss, 2012, p. 141). Also, many factors can affect how an eyewitness remembers things. As Hogg and Cooper (2007) stated, “recent evidence suggests that affective influences on memory may have important practical consequences, for example in the area of eyewitness memory” (p. 158). Because an eyewitness’ description is relying on the person’s memory rather than the facts and truth, such description is often inaccurate due to errors of memory and cognition. On the other hand, even though the information is less accurate, it may still provide valuable data which helps for further investigation.
Costanzo, M., & Krauss, D. (2012). Forensic and legal psychology: Psychological science applied to law. New York, NY: Worth.
Hogg, M. A., & Cooper, J. (Eds.). (2007). The sage handbook of social psychology: Concise student edition. Thousand Oaks, CA: Sage.