The danger of eyewitness mistakes in Tennessee criminal cases

Research shows that various factors can affect the accuracy of memories and increase the risk that eyewitnesses will make misidentifications.

Eyewitness testimony has become a widely accepted, trusted form of evidence, and it plays a role in many Chattanooga criminal cases. Some cases that involve serious felony criminal charges may even be decided largely on the basis of this evidence. Unfortunately, a growing body of research indicates that human memories and evidence based on those memories may not be as accurate as many people would like to believe.

Dynamic memories

A study that analyzed over 30 years of research into eyewitness errors found that the nature of memory often contributes to these harmful mistakes. According to The Washington Post, many people perceive their recollections as static and highly accurate, especially when those memories involve singular or emotional events. However, this perception isn't always correct.

Memories typically evolve over time as people receive new information, forget the original event or struggle to recall it. Some memories may be lost and refabricated, while others might become badly distorted. Troublingly, people don't always realize that their memories have undergone these changes. As a result, eyewitness errors may occur even in cases in which a person initially had a clear and accurate understanding of the event.

Perceptual issues

Problematically, eyewitnesses typically don't see alleged crimes occur under ideal viewing circumstances. Many random, uncontrollable variables can increase the risk that a person will remember an event inaccurately and ultimately make a mistaken identification. As examples, New York Magazine cites the following factors that are often correlated with eyewitness errors:

  • Lighting. According to one study, even eyewitnesses who saw suspects under full moonlight could not accurately identify them later.
  • Emotional distress. Research shows that eyewitnesses who felt fear, anxiety or similar emotions during an incident were more likely to make errors.
  • Weapons. The presence of weapons during violent criminal offenses can produce emotional distress and cause visual fixation, which reduces the likelihood of accurate identifications.
  • Demographic differences. Eyewitness errors also occur more frequently when eyewitnesses and suspects are different ages or have dissimilar racial backgrounds.

Unfortunately, these aren't the only risk factors for errors. The protocols that law enforcement authorities use to conduct lineups can also inadvertently bias witnesses or lead them to make questionable identifications. For example, police officers who know a suspect's identity may unconsciously steer eyewitnesses or give positive feedback after the lineup procedure is over. Consequently, once an eyewitness has made an incorrect identification, he or she may become increasingly convinced of its accuracy.

Devastating consequences

Given all of these potential issues with eyewitness testimony, it's not surprising that many wrongful convictions involve eyewitness errors. According to the Innocence Project, these errors have contributed to over 70 percent of wrongful convictions that were later overturned based on DNA evidence. Here in Tennessee, two out of 13 exonerations that were made in the past 15 years have involved eyewitness mistakes, according to data from the National Registry of Exonerations.

The danger of these errors should be considered carefully any time that a criminal case utilizes testimony from an eyewitness. Seeking the advice of a defense attorney may be a beneficial step for anyone who faces criminal charges that involve this complex and potentially questionable evidence.