Needed: New Legal Procedures

Wells is professor of psychology at Iowa State University.  He is at the forefront of experts who say  the legal system itself is partly to blame  for  eyewitness errors because it is using risky, frequently biased methods to secure eyewitness identification.

There is a growing body of evidence from actual cases showing that mistaken identification by eyewitnesses who are shown lineups and photospreads is the primary cause of false convictions of innocent people in the United States.

Ronald Cotton, featured in the FRONTLINE story, is only one example of an untold number of innocent people who were mistakenly identified by eyewitnesses.

The scientific study of eyewitness identification began in the 1970s. Experimental psychologists, trained in using scientific methods to determine the causes of human behavior, began using staged crimes and other methods to determine what causes false identifications and what might be done to reduce their occurrence in criminal investigations.

The experimental evidence, published in a variety of peer-reviewed scientific journals, shows the risk of eyewitnesses making false identifications is influenced by methods used in constructing and conducting lineups and photospreads. The empirical evidence, and the social and cognitive processes governing these effects indicate that the legal system could impose four simple rules that would greatly reduce the justice system's role in contributing to false identifications:

1) Eyewitnesses should be informed that the culprit might not be in the lineup.

2) The suspect should not stand out as a distinctive member of the lineup.

3) Lineups should be administered by someone who does not know which person is the suspect.

4) Witnesses should be asked how certain they are of their choice prior to allowing other information to contaminate their judgment.

[For a detailed discussion of the scientific evidence on these points, see Wells, G. L. & Seelau, E. P. (1995). "Eyewitness Identification: Psychological research and legal policy on lineups." Psychology, Public Policy, and Law , Volume 1, pages 765-791.]

An examination of the Ronald Cotton case and other cases shows these important safeguards simply were not followed. Consider one of the central "rules" that should be implemented, namely, the person administering the lineup or photospread should not know which person is the suspect. This is standard, widely recognized control in behavioral science experiments that keeps the "tester" from influencing the responses of the person being tested. There is a wealth of scientific evidence showing that a person's expectations, wishes, and hopes unintentionally influence the respondent. In the case of a police investigator administering a photospread for an eyewitness, the investigator's knowledge of which person in the photospread is the suspect creates a dynamic situation in which the investigator can influence the eyewitness to choose the suspect.

For example, eyewitnesses who are shown a photospread commonly sit and stare at it for some time, unable to make a clear identification, until the person administering the photospread says something like, "I noticed that you paused on number three." This communicates to the eyewitness that number three is the suspect. Once the suspect is chosen by the eyewitness, even if the identification is tentative, the investigator can then bolster the eyewitness's certainty in the identification by telling the eyewitness "Good, you got the right guy" or "Yep, that is the guy we thought did it."

Having said this to the eyewitness, the eyewitness then becomes convinced that the identification was correct and a false certainty begins to take hold. Often, the eyewitness will turn to the person administering the photospread and ask "Did I get the right guy?" If the answer at that time is "yes," what possible meaning is there to the eyewitnesses' later answers to the question of how certain they are that they identified the correct person? This kind of influence over the eyewitness's choice and certainty should not be allowed. A rule needs to be imposed on the legal system to have the photospread administered by someone who does not know which person is the suspect, a procedure adopted in behavioral science to guard against undue influence of respondents.

How to Impose Such Rules?

Although the arguments and scientific evidence indicating that these four rules are needed to help reduce the frequency of false identifications, it is unclear how to impose such rules. Media stories, such as the FRONTLINE report featuring Ronald Cotton, can help speed up the rate at which the public becomes concerned and perhaps compel legal policy makers to call for standard rules governing the collection of eyewitness identification evidence.

For additional reading, see:

Wells, G. L. & Seelau, E. P. (1995). "Eyewitness identification: Psychological research and legal policy on lineups" published in the journal Psychology, Public Policy, and Law, Volume 1, pages 765-791.

Wells, G. L., Seelau, E., Rydell, S., & Luus, C. A. E. (1994). "Recommendations for Conducting Lineups" published in the book Adult Eyewitness Testimony: Current trends and developments, (D. F. Ross, J. D. Read, & M. P. Toglia, Editors.), pp. 223-244. New York: Cambridge University Press.

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