You would think the obvious answer to whether or not eyewitness testimony is helpful in criminal cases is fairly straightforward. After all, the eyewitness actually SAW the crime and will testify to it. However, recent research shows that eyewitness testimony may sometimes be unreliable.
In the last several decades, DNA testing has helped to free hundreds of innocent people who were charged with and convicted of crimes they did not commit. Interestingly, over 70% of overturned convictions originally were decided by eyewitness testimony, with about a third of those cases based on the testimony of more than one eyewitness.
Eyewitness testimony is a critical element in criminal cases. Indeed, a confident and believable eyewitness can easily persuade a jury. However, an ever-increasing body of research shows that eyewitness testimony is not always trustworthy, and problems with unreliable testimony can lead to significant miscarriages of justice.
The problem with counting on a memory
Most eyewitnesses are not perjuring themselves and do not intend to give false testimony. Instead, they typically believe they remember something that did not occur with accuracy. The problem with eyewitness testimony is based on how memory functions. While most people think that their memory works like a video recording that they can merely replay, the truth of the matter is that a memory comes together more like a puzzle that is being reconstructed and potentially altered every time it is recalled.
Such false rememberings are a significant problem for the criminal justice system. Eyewitnesses may intentionally or unintentionally create false memories at various phases of a criminal investigation or courtroom trial. For example, an eyewitness may feel pressured to identify a suspect if asked to participate in a police lineup. That pressure may be enough to convince the individual that a specific person in the lineup is the individual that was witnessed committing the crime. This is true even when the person identified in the lineup and the real perpetrator only vaguely resemble each other. False eyewitness identification can become a more significant problem when the suspect is without any stand-out, distinguishing physical features, such as scars or tattoos.
Improving eyewitness testimony
Research into the reliability of eyewitness testimony is ongoing, as is research into finding methods to improve it. However, there are ways to improve police lineup accuracy, in particular. Research suggests that the police officer who is involved investigation should not attend the lineup identification since they are more likely to unconsciously or unintentionally give eyewitnesses subtle clues about which individual in the lineup is the actual suspect. Additionally, people in a lineup should be chosen because they resemble one another, and the eyewitness should be told beforehand that the suspect may or may not be present in the lineup.
Research suggests that eyewitness testimonies should not be the deciding evidence in courtroom trials. As research into eyewitness testimony continues, researchers could find better ways to help jurors understand the potential negatives of relying too heavily on eyewitness statements.
If you have been accused of a criminal offense, you would likely do well to reach out to a criminal defense attorney to get assistance crafting an aggressive and vigorous defense strategy.