Forensic Psychology: Eyewitness Testimony
Eyewitness testimony is a legal term which generally refers to an account given by people who were present at a crime scene, describing their perception of happened during the incident of the crime. Eyewitness misidentification is the leading cause of wrongful convictions in the United States (Scheck et al., 2007). DNA evidence has been used to exonerate nearly 200 individuals who were wrongfully convicted and of those (Scheck et al., 2007), approximately 75% were convicted due to inaccurate and faulty eyewitness idenfications (The Innocence Project, n.d.). Many studies performed by psychologists have found that there are many psychological factors influencing an eyewitness’ perception of the crime, such as reconstructive memory and weapon focus. Due to these psychological factors having a huge effect on how an eyewitness perceives a crime scene, eyewitness testimony is unreliable and the eyewitness identification system should be altered or there should be alternative methods for identifying the perpetrator of a crime.
Memory does not work like a videotape, in fact it is a feature of human nature that does not store information exactly as it is presented. Instead, people store information in the way that makes the most sense to them so each time a memory is revisited, details may be changed and gaps can be filled, based on new knowledge gained or an altered perspective on an event. In other words, people store information in a way that makes sense to them by trying to fit it into schemas, which are ways of organising information. However, by forcing new situations to fit into schemas, they may be distorted. Reconstructive memory is a theory of memory recall where the act of remembering is influenced by various cognitive factors such as perception, imagination, beliefs etc. Frederic Bartlett supports this theory in his famous study “War of the Ghosts” (Bartlett, 1932). In this study, he showed that what the human brain remembers isn’t the factual recording of the occurrence, but that people make “effort after meaning”. This means that people try to connect what they remember with their own knowledge and understanding about the world. As a result, a lot changes from people’s memories so that it makes sense to them. The study involved participants hearing a story, then retelling the story to another person and so on, similar to the game “Chinese Whispers”. The story was a North American folk tale called “The War of the Ghosts”. The participants were asked to recount the story and it was found that each person recalled the story in their own individual way. The passages shortened, puzzling ideas were edited or removed together and details changed to become more rational or conventional. For example, details and information about the “ghosts” was omitted as it was difficult to explain. This Bartlett study clearly indicates that memory is anything but reliable. They are individual recollections shaped and constructed according to stereotypes, beliefs, expectations etc. Although some may believe that reconstructive memory further helps the eyewitness identify the perpetrator by filling in missing gaps and improving their perception of what had happened in the event, this argument wouldn’t be valid as the information filling the gaps are merely assumptions rather than facts.
It has been assumed that people have a limited capacity for processing information because there is always a huge amount of information to absorb from the environment. Usually, people tend to pick out the more relevant or important information that may draw attention. Weapons and other threats are one example. Weapon focus is when an eyewitness’s concentration focuses on a weapon to the exclusion of other details of the crime as that would seem like the most obvious threat. When weapons are involved in a crime, it is quite common for an eyewitness to be able to describe the weapon in much more detail than notice