Dr. Karen L. Amendola, the Police Foundation’s Chief Behavioral Scientist, presented testimony in April to the Committee on Scientific Approaches to Understanding and Maximizing the Validity and Reliability of Eyewitness Identification in Law Enforcement and the Courts, who prepared the report. Dr. Amendola has been conducting research on the effectiveness of law enforcement practices used in eyewitness identification with Dr. John Wixted, a distinguished professor of psychology at the University of California, San Diego. Their research is forthcoming in the Journal of Experimental Criminology.
The National Research Council report, which was sponsored by the Laura and John Arnold Foundation, came in response to long-standing concerns with eyewitness identifications. In some high-profile cases that depended on eyewitness identification, the person convicted was later exonerated by DNA evidence by groups like the Innocence Project. Research has shown that dim lighting, brief viewing times, stress, or the presence of a visually distracting element such as a gun or knife can reduce the accuracy of a witness’s perceptions. Studies have shown that eyewitnesses are more likely to make mistakes when making an identification among people of another race, according to the report.
“The Laura and John Arnold Foundation should be commended for their support of this important work, and the NRC for producing such a high quality, comprehensive, and balanced report,” Dr. Amendola said. “Among the most important recommendations is that law enforcement agencies should provide training to all officers and agents about vision and memory (and associated variables), practices for reducing contamination, and on effective eyewitness ID protocols.”
“This may prove a daunting task; just who should develop and deliver that training, and what should it contain?” Dr. Amendola said. “The fact that this body of research is immense and heavily scientific, means the challenge that we will face is how best to translate that science in ways that are clear and effective in ensuring consistency in understanding and practice.”
Many law enforcement agencies have attempted to improve the accuracy of eyewitness identifications, but results have been mixed, according to the report. Some policymakers have urged police departments to use sequential lineups – in which the witnesses are shown one person or photo at a time — instead of simultaneous lineups, which show several people or photos at once. But the Committee found that additional research is needed to determine which procedure is superior, the report says.
To increase the likelihood of accuracy in eyewitness identifications, the report recommends that law enforcement agencies use the following practices in handling eyewitness identifications.
- Train all law enforcement officers in eyewitness identification. All law enforcement agencies should provide their officers and agents with training about vision and memory, practices for minimizing contamination, and effective eyewitness identification protocols. Police officers should be trained to ask open-ended questions, avoid suggestiveness, and efficiently manage scenes with multiple witnesses (for example, by minimizing interactions among witnesses).
- Implement double-blind lineup and photo array procedures. Even if a line-up administrator does not tell the witness which person is the suspect, unintended body gestures, facial expressions, or other nonverbal cues could convey that impression. By using a double-blind procedure, in which neither the witness nor the administrator knows which person is the suspect, one can avoid this inadvertent bias.
- Develop and use standardized witness instructions. The report recommends the development of a standard set of easily understood instructions to use when engaging a witness in an identification procedure. Witnesses should be instructed that the perpetrator may or may not be in the photo array or lineup and that, regardless of whether the witness identifies a suspect, the investigation will continue.
- Document witness confidence judgments. Evidence indicates that an eyewitness’s level of confidence in their identifications at the time of trial is not a reliable predictor of their accuracy. Law enforcement should document the witness’s level of confidence verbatim at the time when she or he first identifies a suspect.
- Videotape the witness identification process. To obtain and preserve a permanent record of the conditions associated with the initial identification, the committee recommended that video recording of eyewitness identification procedures become standard practice.