The weight of eyewitness testimony in a criminal trial

Eyewitness testimony is a critical part of many criminal trials in Illinois and across the country. People who were present at the scene of the crime often tell their accounts of what happened when the crime occurred. The judges and juries listening to these eyewitness accounts place heavy weight on the details of their stories. In fact, testimonies may sway the jury to declare the defendant guilty or not guilty, simply based on the account of one or more people. What many people don’t realize, however, is that many of these accounts are not accurate and are often unreliable when it comes to giving solid facts regarding the crime. Eyewitness misidentification, environmental influences and limitations of the human memory can all cause errors and potentially send an innocent person to prison.

One study looked at the influence that eyewitness testimony has on jurors and their decisions regarding a crime. In one case, jurors were presented with circumstantial evidence of a robbery-murder. Approximately 18 percent of these jurors came back with a guilty verdict. During the second case, the same circumstantial evidence of the same crime was presented to the jury, with a single eyewitness testimony added to the case. A clerk who was at the scene of the crime named the suspect as the perpetrator. A surprising 72 percent of the jurors came back with a guilty verdict in this instance.

Multiple studies show how flaws in the eyewitness identification process, including misleading comments made by lineup administrators and time elapsed between the crime and the date of the lineup, can cause a witness to choose the wrong person out of a lineup.