Eyewitness accounts highly flawed, study says
A Yale University study suggests that eyewitness testimony may not be all it’s cracked up to be.
Stressful conditions impair the accuracy of making an identification, said Dr. Charles Morgan III, an associate professor of psychiatry at Yale University School of Medicine. His study was carried out on 509 military personnel participating in a survival training camp.
During the training, they were subjected to mock POW interrogations. Half were exposed to a high-stress 30-minute interrogation that included the threat of physical violence. Twenty-four hours later, they were asked to identify the interrogator in a line-up, a photo spread or a series of photos. The results: 30 percent accuracy in the live line-up, 38 percent accuracy in the photo spread and 49 percent accuracy in the series of photos.
By comparison, the other half of trainees, in less threatening interrogations, were able to pick out their interrogators with greater accuracy, from 62 percent in the live line-up to 76 percent in the series of photos.
“This is the study we have been waiting for,” said Elizabeth Loftus, a psychologist at the University of California at Irvine and an expert on the accuracy of eyewitness testimony. Loftus’ work over the past two decades has shown that memory may seem vivid but is often inaccurate and distorted.
The scientists also wanted to know how accurate people were in being able to say “no” when the interrogator was not included in the line-up or photos. The high-stress group said “no” with 100 percent accuracy when shown a series of 12 photos. But they said “no” only 55 percent of the time in the live line-ups and 52 percent of the time when shown the photo spreads.
The low-stress group fared much better on these experiments. “Prosecutors argue that the poor victim was so shocked that she’d never forget that face,” Loftus said. “This study suggests that they do forget.” She said a major cause of wrongful convictions is faulty eyewitness testimony. “This study proves that you can be up close and personal and a short time later not be able to recognize your perpetrator,” she said.
Saul Kassin of Williams College in Massachusetts argues that this finding makes it necessary to videotape criminal interrogations because memory is so faulty. “It’s a way to preserve the actual memory,” he said. He suspects that stressful conditions force people to narrow their focus to a few details.