Human memory is not flawless, as most people in Greeley recognize. Still, despite knowing this, people are often inclined to believe recollections of traumatic events, such as assault or rape, which is why eyewitness evidence can be decisive in many criminal cases. Unfortunately, research indicates that even memories of these events can be inaccurate.
Proper eyewitness identification
procedures may reduce the risk of errors,
but human memory itself is problematically
dynamic and prone to distortion.
The National Academy of Sciences recently released a report on the accuracy of human memory and eyewitness testimony. According to The New York Times, the report recommends changes to law enforcement procedures, such as recording identifications, to help prevent wrongful convictions. Still, a growing body of research suggests eyewitness inaccuracy doesn't just arise due to issues with identification procedures. The nature of memory itself also puts eyewitnesses at risk for errors.
Factors Influencing Initial Eyewitness Accuracy
The Innocence Project explains that several variables can affect how well an eyewitness views an alleged crime or processes what occurs. Examples of these estimator variables, which are often random and beyond anyone's control, include the following:
- The distance from which the witness viewed the suspect
- The level of fear or anxiety the witness felt during the event
- The distracting presence or use of a deadly weapon
- The race of the witness and suspect
All of these factors can contribute to a flawed memory of the initial event, which may only become more inaccurate as the witness recalls and reexamines it over time.
Gradual Memory Distortions
Humans don't have perfect recall; memories are altered or reconstructed regularly, often with a bias toward present-day knowledge. According to USA Today, one study suggests the part of the brain that stores and recalls memories may also alter them. The study found that memories can be tweaked to fit current views, or they can be updated to incorporate information that was not available in the past.
The New York Times notes that the degree of excitement or stress involved in a memory does not predict accuracy, even if the memory seems vivid afterward; similarly, the confidence a witness expresses in a statement or identification does not always correlate with accuracy. It's intuitive to think witnesses would express a lower degree of confidence in memories that are inaccurate. However, research shows that witnesses are often highly confident in both correct and incorrect identifications.
The Wrongful Conviction Risk
Eyewitness errors are a common contributing factor in wrongful convictions; the Innocence Project reports that 72 percent of convictions overturned through DNA testing have involved some form of eyewitness error. This risk, and the science behind human memory, should be considered in any criminal case using eyewitness evidence. Fortunately, in Colorado, experts in eyewitness science may be permitted to testify in these cases, since eyewitness accuracy may be a relevant factor in the case.
Anyone facing criminal charges based on eyewitness testimony should consider speaking with an attorney about the best means of addressing those charges.