Eyewitness testimony is a form of legal testimony presented by someone who was a direct witness to the events being discussed in a trial or hearing. This type of testimony can be very powerful during a trial, especially for a jury that feels a witness and his or her account are reliable and accurate. There is a certain amount of controversy and debate over the use and importance of this testimony, however, as a great deal of research has indicated a number of intrinsic flaws with human perception and memory, including the retelling of events in eyewitness testimony.
Testimony is a form of evidence typically allowed in a criminal or civil trial or hearing, which refers to opinions or events relayed by a person in spoken or written form. Eyewitness testimony specifically refers to such evidence that is relayed by a person who directly witnessed the events being discussed. This type of testimony can come from the victim in a crime, the suspected perpetrator of the crime, or a witness who was not personally related to the events that occurred. Much like other forms of evidence, eyewitness testimony is typically presented by either the prosecution or the defense and is subject to cross-examination.
Eyewitness testimony is generally considered to be one of the most important forms of evidence used during a trial. A great deal of credibility is often granted to someone giving an eyewitness report of what occurred, which can ultimately help or hinder a case more than many other types of evidence. There is some debate over the reliability of such evidence, however, and much of this concern stems from research performed by psychologists on the ways in which eyewitness testimony can be remembered and recalled.
While purposeful deception in eyewitness testimony is illegal, there is a tendency for a witness to alter his or her recollection of events without even being aware that he or she is doing so. Research into memory and recollection has shown that people often recall events or tell a story to someone with a particular purpose, often one that is subconscious, in mind. When someone recalls events to a police officer, for example, then he or she is trying to provide the officer with information that can be helpful, including evidence that will help identify and incriminate the offender.
Afterward, however, he or she will continue to tell the story of what happened in a way that is similar to the first telling. This usually includes providing details aimed at prosecuting the perpetrator rather than a purely unbiased retelling of events. Even the ways in which questions are asked, including exact language used, can have a tremendous impact on the accuracy of eyewitness testimony.