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To Err is Human: Using Science to Reduce Mistaken Eyewitness Identifications Through Police Lineups

NCJ Number
NIJ Journal Issue: 270 Dated: June 2012 Pages: 30-34
Date Published
June 2012
5 pages
Publication Series
This article reviews the findings of studies that have compared the reliability of eyewitness identifications of suspects in "sequential" and "simultaneous" lineups.

In the "sequential" lineup, eyewitnesses view lineup members one at a time and make a decision on each individual in the lineup. In the "simultaneous" lineup, eyewitnesses view all members of the lineup together. The first set of studies reviewed consisted of laboratory experiments, which found that sequential lineups produce a better ratio of accurate to mistaken identifications compared to simultaneous lineups. Although laboratory results were promising, proposed changes in investigative practices needed to be field tested before widespread procedural changes are warranted. A 2006 study conducted with the Illinois State Police (the "Mecklenberg" report) found that in two of the three jurisdictions participating in the study, double-blind, sequential lineups produced a higher rate of identification of "fillers" (persons known to be innocent) and a lower rate of identification of suspects, thus contradicting the findings of laboratory experiments. In order to address criticisms of the study's methodology, the American Judicature Society (AJS) convened scientists, lawyers, prosecutors, and police in Greensboro, NC, to develop a set of guidelines for conducting field experiments for testing the simultaneous/sequential variable. This resulted in the Greensboro Protocols, which emphasized the importance of true random assignment of lineups into the sequential or simultaneous groups. The consistent use of double-blind lineups in both groups is also deemed essential for conducting a scientifically sound field experiment. Relying on the Greensboro Protocols, the AJS developed a field experiment that compensated for the deficiencies of the 2006 Illinois study. This study found that sequential lineups reduced mistaken identifications without significantly reducing accurate identifications. Next steps in the research are outlined. 23 notes

Date Published: June 1, 2012