While very dramatic at trial, eyewitness evidence can be unreliable. Numerous scientific studies have been conducted on the accuracy of eyewitness identification. Some social scientists estimate that erroneous eyewitness identification is responsible for a significant percentage of incorrect convictions. However, jurors tend to believe that eyewitness testimony is accurate. This article discusses the factors that affect the accuracy of eyewitness identification and what the courts are doing to reduce the number of incorrect convictions.
Factors that Affect the Accuracy of Eyewitness Identification
Initial perception of the event or the suspect. Several factors can influence an eyewitness's initial view of the event or the suspect. For example, research has shown that a witness threatened with a knife or gun focuses more on the weapon than on the suspect. Also, the length of time a suspect is observed, along with distance and lighting, can affect the eyewitness's ability to recall the suspect's appearance. The stressfulness of the event also can affect the recollection of the eyewitness.
Memory retention. The length of time between the eyewitness's viewing of the suspect or the event and the time when the eyewitness is asked to recall the information can affect the accuracy of the memory.
Memory recall. Various factors can affect the recall of the event or the suspect and lead to a misidentification. Generally, the elderly tend to have less accurate recall, and both children and the elderly are more affected by suggestive questioning. Men and women tend to recall different types of information. Also, a person has greater recall of faces from a person's own race than for the faces of another race. Women tend to remember female faces better than males do.
Expert Testimony about Eyewitness Evidence
The majority of state and federal courts holds that the trial judge has discretion to admit or exclude expert testimony about the reliability of eyewitness identification.
Cautionary Jury Instructions
Some courts use special cautionary jury instructions covering the factors that can affect the accuracy of eyewitness identification. These factors include the opportunity of the eyewitness to view the suspect during the crime or event, the length of time between the crime or event and the eyewitness identification, and the level of certainty shown by the eyewitness during the identification. However, some observers believe that such cautionary instructions are ineffective.
Copyright 2012 LexisNexis, a division of Reed Elsevier Inc.