Inoculating Eyewitnesses Against Errors

Media contact: January 3,
George Chartier
703) 306-1070/[email protected]

Program contact: Harmon Hosch (703) 306-1762/[email protected]

FALSE IDENTIFICATION: NEW RESEARCH SEEKS TO INOCULATE EYEWITNESSES AGAINST ERRORS

More than 75,000 people become crime suspects each year in the United States based on being identified from lineups and photo spreads. Some identifications will be false and lead to mistaken arrests and imprisonments.

A recent study* reveals the extent of this problem. In 24 of a sample 28 cases involving Americans who were released from prison in the last few years based on DNA evidence that proved their innocence, eyewitnesses had made false identifications from photo spreads and lineups. No one knows how many others may be unjustly jailed every year due to false identifications.

New research sponsored by the National Science Foundation (NSF) is now helping to understand the circumstances that lead to false identifications and to find ways to reduce their occurrences. The results should eventually help police and jurors who must decide the fate of a suspect based on the confidence of an eyewitness account.

*Connors, E., Lundregan, T., Miller, N. & McEwan, T. (1996). Convicted by juries, exonerated by science: Case studies in the use of DNA evidence to establish innocence after trial. Alexandria, Va.: National Institute of Justice.

Particularly troublesome, says Gary Wells, a psychologist at Iowa State University who has conducted NSF-funded research in this area, is evidence that an objective question such as ìHow certain are you that the person you identified is the person you saw commit the crime?î elicits a similar response regardless of whether the eyewitnessí memory is accurate or not.

This discovery surprised Wells and his team of researchers, who hoped a direct question would counteract certain influences on an eyewitnessí memory. They knew that confidence can be manipulated easily if eyewitnesses receive information about a suspect after making an identification. Their earlier research indicated that casual remarks (ìYes, youíve identified the same suspect we picked up for questioningî) uttered by police station personnel administering suspect lineups or photo spreads can bolster the confidence of an eyewitness and distort the witnessí memory.

The latest research funded by NSF reveals that, once an eyewitnessí memory has been distorted in this way, a straightforward cross-examination often fails to produce an accurate recollection. In particular, eyewitnesses began to change their answers to questions about how much attention they had paid to the culprit, how good a view they had of the culpritís face, and other factors surrounding the event. As a result, Wells believes stronger steps are needed to ìinoculateî eyewitnessesí memories, especially over the weeks and months that may stretch between the crime and a courtroom trial.

ìWe know the nature of the problem,î says Wells. ìNow we need to look at ways to prevent manipulation. Part of the solution is to require blind testing, where the person administering line-ups or picture spreads does not know who the suspects areî and therefore cannot bias the eyewitness, he says.

Wells also suspects that more accurate testimonies may result from posing a series of deliberate questions immediately after identification to probe an eyewitnessí confidence and memory. Questions such as ìHow clear a view did you have of the suspect?î ìHow long did you look at him?î ìHow easy was it for you to make the identification from the photo spread?î may help reduce later distortions of their answers, he says. This is his next line of study.

To test the accuracy of eyewitness testimonies, Wells and his team staged thefts and possible acts of fraud before unsuspecting potential eyewitnesses in offices, stores and waiting rooms; the eyewitnesses then were asked to make identifications under various conditions which isolated factors that could affect the confidence of their memories.

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