Questioning eyewitness accuracy in Colorado criminal cases
Since eyewitness memories can be influenced by variables at the crime scene and police protocols, eyewitness evidence is often questionable.
Human memories can be vivid, especially in situations involving shock or duress. Not surprisingly, many people in Boulder think this means eyewitnesses to events such as crimes usually provide detailed, correct accounts. In reality, eyewitnesses often make mistakes when they witness crimes such as theft or assault. The limitations of human memory and the factors known to affect eyewitness perceptions should both be carefully accounted for in any criminal case involving eyewitness testimony.
When eyewitnesses are inaccurate
The Innocence Project reports that eyewitness misidentifications contributed to 72 percent of wrongful convictions that were eventually exonerated through DNA testing. This high rate of contribution, along with decades of research into the nature of human memory, suggests eyewitness errors are fairly common occurrences, rather than isolated events. Human memory is more dynamic than people realize, and it is susceptible to errors both during the formation of memories and later recall.
Estimator variables, which occur at the scene of the alleged crime, can affect how well an eyewitness takes in an event. Factors such as lighting, distance and duration of exposure affect how well the witness can physically view the scene. Psychological factors, such as eyewitness stress due to the presence of a weapon during a theft or assault, can prove distracting. Other factors, such as racial disparity between the eyewitness and alleged offender, reduce the likelihood of a correct identification.
System variables, which arise from criminal justice procedures, also affect the way an eyewitness recalls an event. The instructions the eyewitness receives, the choice of “fillers” in the lineup and the way authorities speak to the eyewitness can all lead the eyewitness or instill a false sense of confidence. Authorities who know the suspect’s identity may pass on unwitting cues to the eyewitness. These variables must be carefully controlled during identification procedures to reduce the risk of a false identification.
Improved identification procedures
According to the Washington Post, the National Academy of Sciences recently released a report on eyewitness identifications. The report recommended that law enforcement authorities start using the following uniform procedures, which are designed to not bias or lead witnesses:
- The identification procedure should be recorded.
- The lineup or photo array should be blind; in other words, any authorities overseeing the procedure should not know the identity of the suspect.
- Eyewitnesses should be advised that the investigation will proceed whether or not a suspect is identified, since the offender might not even be present.
- Eyewitnesses who identify a suspect should be asked to give a confidence statement immediately afterward, before receiving any feedback that creates false confidence in the identification.
Unfortunately, even with these safeguards, uncontrollable estimator variables may still impede an eyewitness’s ability to accurately view and process a scene. This means eyewitness testimony should always be considered with caution during criminal proceedings.
Anyone facing criminal charges in a case involving eyewitnesses should meet with an attorney for advice on defending against the charges.
Keywords: eyewitness, evidence, wrongful conviction