Crime Eyewitness Easily Swayed by Cops, Study Finds

by Doug Fizel
American Psychological Association

Fingerprints, DNA matches and fibers may be more reliably objective indicators that a suspect committed a crime, but studies have found that most jurors trust the testimony of an eyewitness, even when the eyewitness is completely wrong. Research has shown that incorrect eyewitness identifications account for more convictions of innocent persons than all other causes combined.

Now a new study reported in the June edition of the Journal of Applied Psychology provides even further evidence that eyewitness testimony may not deserve the confidence that many jurors have in it.

In the two studies, which involved a total of 352 people, the researchers had participants watch a grainy surveillance camera videotape of a person who later shot and killed a store security guard. They were then presented a photospread of five faces that did not include the actual gunman, but were asked to identify the man they had seen on the videotape.

After the participants in the first study made their identifications (which were, of course, always wrong), they were randomly told: "Good. You identified the actual suspect in the case." or "Oh. You identified number X. The suspect is number Y." or they received no feedback. The participants then filled out a form that asked a long series of questions about their view of the gunman, how well they were able to make out specific features of the gunman's face, and so on.

As expected, those who received positive feedback were more confident of their identification than those who received either negative feedback or no feedback at all (even though all participants were equally wrong). However, the positive feedback about the supposed accuracy of their identification seemed to make them remember almost everything about their identification differently.

In addition to being more confident of their choice of photographs, they also remembered having a better view of the culprit, having paid greater attention to the videotape, having had an easier time making the identification, needing less time to make the identification and being better able to make out details of the culprit's face than those who received negative feedback or no feedback.

Positive feedback distorted the witnesses' reports of almost every aspect of the identification process. It served, the authors say, "to manufacture credible witnesses from a pool of inaccurate witnesses who were not particularly credible on their own. We are alarmed at these findings."

The second study also found positive feedback influenced eyewitness indentification, even though most eyewitnesses denied it. But the second study also found a potential antidote to the influence of positive feedback: asking questions before giving feedback. In this study, some participants, randomly selected, were asked how confident they were about their identifications before receiving any feedback. The authors say asking such a question -- and probably others -- might help prevent eyewitnesses from being unduly influenced by positive feedback.

In real cases, the authors say, feedback might even have stronger effects. Another reason for alarm is the fact that the criteria most courts use to determine the likely accuracy of an eyewitness's identification of a criminal suspect -- presumably to keep eyewitnesses who are not credible off the stand -- would have no effect in detecting or countering feedback-caused memory distortion.

Based on these findings, the authors strongly advocate that lineups and photospreads be supervised by someone who does not know who the suspect is and that eyewitnesses at least be asked about their confidence -- and have their responses recorded -- "at the time of the identification, rather than after there is an opportunity for other events to influence the eyewitnesses' confidence and other judgments."