Fallibility of Memory, Perception, and Vision in Eyewitness Testimony

¶ … eyewitness testimony is far from being a gold standard in criminal justice. At least 75% of wrongful convictions for violent crimes including rape and murder were based on eyewitness testimony, and many of those convictions led to the death penalty (Bohannon 2014). Stambor (2006) found that 78% of wrongful convictions were based on overreliance on eyewitness testimony. It is therefore critical to reexamine the policies and procedures surrounding the collection and use of eyewitness testimony in criminal cases. Emerging research in perception, cognition, and the study of memory provides the framework with which to base a reform of criminal justice procedures. Training of police officers, and a comprehensive debriefing of judges, juries, and the witnesses themselves, are also possible solutions for minimizing problems with eyewitness reports. Although eyewitness testimony can be tremendously helpful in criminal cases, the evidence must be analyzed in a scientific and systematic manner.

Some of the problems that may affect the validity of eyewitness testimony include being under stress during the event witnessed, being under stress during interrogation or later recall, being coached, even subtly, during interrogation, being coached, albeit subtly, during lineups, problems with officers using leading questions as opposed to open-ended ones, and the problems related to memory, perception, and cognition. During lineups, police officers often divulge cues unconsciously but subconsciously perceived by the eyewitness. For example, "A detective might smile, grunt, or nod approvingly when a suspect is chosen," (Bohannon 2014). Asking leading questions can distort memory or create false memories (McLeod 2009). Eyewitness recall can be affected by any number of factors. "Although the individual may be unaware of it, memories are forgotten, reconstructed, updated, and distorted," (National Academy of Sciences 2014).

Moreover, memories are often constructed to fit schemas. Stereotypes and subconscious racism and other biases can greatly affect the accuracy of an eyewitness recall. According to the National Academy of Sciences (2014), "eyewitnesses are more likely to make mistakes when making an identification among people of another race rather than when making an identification of a person from the eyewitness's own race." Eyewitnesses also have trouble identifying faces when there was a weapon present during the witnessed event. Known as "weapon focus," the tendency for the mind to focus on the details of the weapon as opposed to the face of the person wielding the weapon, is a well-documented issue related to the validity of eyewitness perception (McLeod 2009). Other aspects of the visual system impact the reliability of eyewitness testimony, such as lighting and distance. The greater the distance between eyewitness and suspect, the less likely the eyewitness can accurately pull the correct person out of a lineup, which is why vision testing may be a necessary solution to problems related to eyewitness identification.

The media and other social influences can impact recall. "Careful studies have demonstrated that, regardless of the level of certainty an eyewitness expresses at the time of original identification…a witness's confidence in the correctness of the identification steadily increases over time," (Albright & Rakoff 2015). In other words, the witness becomes more certain that the person they picked out of the lineup was the correct suspect not based on actual evidence, but based on the construction of false memory. The implications of these findings are huge, as the eyewitness might have had a small to moderate degree of certainty that a certain subject was the culprit, but may be influenced by media coverage and police discourse to the point where the witness becomes psychologically convinced and thus, convinces a jury to convict. This is why it is necessary to tightly control for witness exposure to the media and other contaminating influences.