Eyewitness Testimony…the Gold Standard?
Eyewitness testimony is understood by most people to be the gold standard when it comes to reconstructing the details of certain events that haven’t been documented by any other means. This belief comes into question when any number of people can witness a crime in progress and later report substantially different accounts than others witness present at the same event. Seemingly obvious items like gender, hair color, or if the person was wearing a hat can vary. In is further astounding when those same witnesses will later provide totally different details of the incident to another questioner.
This situation is most unfortunate because the foundation of the American judicial process is the reliability of witnesses, especially in a courtroom setting. Eyewitness testimony can make a deep impression on a jury, which is often exclusively assigned the role of sorting out credibility issues and making judgments about the truth of witness statements. Our evidentiary system presumes the reliability of eyewitness testimony unless it has been tainted by official action, as when a judge tells jurors to disregard a witness’s testimony. Jurors, too, often will assume the reliability of first-hand accounts of a crime’s details and tend to over-credit eyewitnesses.
Knowing that the system depends on factual truth, perjury is a crime, because lying under oath can subvert the integrity of a trial and the legitimacy of the judicial system. Perjury is a crime defined as knowingly making a false statement under oath and while merely misremembering is not a crime. In a jury trial, misremembered testimony is functionally the same as perjured testimony when it comes time to read the verdict.
Memory is not a Cell Phone Video
We all know how our memory works, or at least we think we do. Some events we firmly believe are burned permanently in our memory. In our mind’s eye, we “see” just what has happened.
We think our memory works like a cell phone video: the mind records events and then, on cue, plays back an exact replica of them. This, however, is not what study of memories has shown. Psychologists have found that memories are reconstructed rather than played back each time we recall them. The act of remembering, says eminent memory researcher and psychologist Elizabeth F. Loftus of the University of California, Irvine, is “more akin to putting puzzle pieces together than retrieving a video recording.” Even questioning by a lawyer can alter the witness’s testimony because fragments of the memory may unknowingly be combined with information provided by the questioner, leading to inaccurate recall.
Decades of research show that memory is neither precise nor fixed. Even after hearing the statistics, we are reluctant to distrust a sincere eyewitness. For instance, we would expect a moment of high stress to focus the mind and sharpen recall, but the opposite is true. Violence, stress, and the presence of a weapon during an incident actually weaken memory. Racial differences between the witness and the suspect can impair identifications. Unconscious transference, or confusing someone seen in one place with someone seen in another place, is common. Identification can also be impaired by how long the witness is exposed to the suspect, the delay between the incident and the identification, and post-event information, such as feedback from the police or other witnesses.
Eyewitnesses to A Story of National Importance
For those who followed the Ferguson case from the first Anderson Cooper interviews on CNN through the unprecedented release of the grand jury proceedings, the stories of eyewitness variability are familiar and unnerving. Some witnesses stuck to their stories, even when their recollections were physically impossible. One witness claimed to have specific knowledge of events even though she had taken shelter behind a dumpster at the time when the events occurred. Other, more creditable witnesses had given police one account of events and then presented modified accounts to the grand jury. Some had watched various videos of the shooting and made their grand jury testimony conform to what they had viewed.
Ultimately, the Grand Jury panel of nine white and three black members heard 70 hours of testimony from 60 witnesses and three medical examiners. They declined to indict Officer Darren Wilson in Michael Brown’s death. After the decision was announced, the St. Louis County Prosecuting Attorney’s Office did something that almost never happens. They released transcripts of the proceedings, giving observers a rare glimpse into the closed-door hearing.
It may have been motivated by the desire of the prosecutor to demonstrate the utmost transparency in a volatile, highly political case, but, among other notable items, it exposed to public scrutiny redacted police statements and contradictory autopsies. Most telling were the conflicting witness accounts, which only seemed to leave a murkier picture of what happened.
Far from what many of the eyewitnesses had hoped, their testimony only added to the confusion, rather than help create a clear cut account of the shooting.
Visual Identification as Eyewitness Testimony
One common form of eyewitness “testimony” is purely visual and it relies on the same memory as a verbal account. The eyewitness selects the alleged perpetrator from a police lineup, or from police sketches and other facial compositing methods. Soon after selecting a suspect, eyewitnesses are asked to make a formal statement confirming the ID and to try to recall any other details about events surrounding the crime. At the trial, which may be years after the incident, eyewitnesses usually testify in court. It is an unfortunate fact that individuals with an unusual visual presence, for whatever reason, puts them at heightened risk for false identifications by eyewitnesses.
Factors Affecting Eyewitness Evidence
The New Jersey Supreme Court has made a detailed study of the factors affecting eyewitness evidence and divided these factors into two categories. In general, there are things that can be controlled by the criminal justice system and those that are beyond the control of the system.
Of the things that can be controlled by the criminal justice system, predominant is the photographic or physical lineup. Studies show that witnesses select the wrong suspect from a photo lineup roughly a quarter of the time. When the suspect is left out of a lineup, witnesses pick an innocent person more than a third of the time – even when told that the suspect may not appear in the lineup.
Lineups are responsible for many mis-identifications, but there are practical steps that a law-enforcement agency can take to minimize error, and for litigants, the absence of these steps can raise a red flag.
Lineups should be blind or double-blind, meaning that the officer administering the lineup does not know who the suspect is. This removes the danger of unintentional suggestion. The officer should emphasize that the suspect may not appear in the lineup. The witness should not feel obligated or pressured to pick anyone.
Of course, lineups should be constructed so that the suspect does not stand out. Photos should have similar lighting, and headshots should be the same size. Errors tend to increase when there are too many photos to choose from; the optimal number seems to be six. Two suspects should not appear in the same lineup. Multiple viewings of the same suspect should be avoided.
The police should carefully avoid post-identification feedback or confirmation, which can create a false sense of confidence in a witness. If a witness hears that he or she did a “good job” picking a certain face, even the wrong one, she is more likely to repeat the mistake at trial. For the same reason, multiple witnesses to the same event should be told not to discuss the identification procedure with other witnesses.
“Show-up” identifications, where the police produce a single suspect for identification, are inherently suggestive, although sometimes necessary. The accuracy of a show-up identification diminishes quickly following an event, so show-ups should be used, if at all, within two hours of the event.
Variables beyond the Control of the Criminal Justice System
Some variable, which can often be the deciding factors in any given case, are beyond the control of the criminal justice system. They can directly affect a person’s ability to perceive and recall.
A person under high psychological stress at the time of an event is less likely to make a reliable identification later. Studies of eyewitnesses, including one controlled study of military personnel, consistently show that high stress impairs recall and identification.
When a weapon is present during an event, it can distract the witness’s attention away from the suspect and lead to poor descriptions and mis-identification later, especially when the event has a short duration. Weapon focus has been shown to decrease the accuracy of identifications by about 10 percent.
Other uncontrollable variables are influenced by a witness’ personal perceptions. Distance, lighting, and how long a witness had to view the suspect are all important, as are the witness’s own characteristics, such as age, race bias, or level of intoxication. Personal characteristics of the suspect, even something as simple as wearing a hat or different facial hair, have been shown to affect identifications.
Memory decay is inevitable and irreversible. The more time that passes between the event and the identification, the more likely a witness is to misidentify or fail to recall a suspect.
This is particularly a factor with trials that consume whole decades, but the system can minimize its effect by staging identifications as soon as possible after the event.
We Should Rethink the Value of Eyewitness Testimony
In light of scientific evidence and just as important, practical experience, it appears increasingly apparent that the American public and the judicial system in particular should rethink the value of eyewitness testimony and visual identifications. To totally dismiss them would unnecessarily discard the valuable information they can provide in many situations, however. What this type of evidence calls for is recognition on the part of judges, juries and the general public that eyewitness accounts do have their limits and we should take them into account.
The recent calls for police body cameras seem to be an attempt to come up with a less impeachable source of eyewitness accounts, but this technology, too, must be interpreted by people. The human variable has always been and always will be the determinant factor in whatever technology or methodology we might bring to bear on the problems associated with eyewitness evidence.