Faulty eyewitness identification is the leading cause of wrongful convictions – nationally, 75% of faulty convictions have involved mistaken identifications by witnesses. But exactly what procedures reduce the incidence of mistaken identification has long been a subject of controversy. According to a new field study released this week, a double-blind sequential lineup – in which the administering officer doesn’t know which person in a lineup is the suspect and photos of individuals in the lineup are presented to witnesses one at a time – reduced the number of mistaken IDs of “known innocents” by 18%. The sequential procedure appears to be more accurate because it “forces witnesses to use a more absolute” process, comparing their recollections to individual photos, rather than making “relative judgements” about which person looks more like a suspect when presented with a simultaneous lineup, or six photos shown together, Gary Wells, an Iowa State psychology professor and a nationally recognized expert in eyewitness identification, said during a telephone press conference Sept. 19. The field study also involved actual cases and eyewitnesses to crimes, as opposed to previous laboratory studies with “witnesses” in controlled situations; as such, the study offers real-world conclusions that should help law enforcement officials focus on best practices, other experts said.
The press call’s participants included Austin Police Department Chief Art Acevedo and Travis County District Attorney Rosemary Lehmberg. Lehmberg says the study’s results will help the Bill Blackwood Law Enforcement Management Institute at Sam Houston State University develop a model eyewitness ID policy for all Texas police agencies, which was mandated by a bill passed in the Texas Legislature this spring. That law has been criticized for not doing enough. For example, there’s no penalty for police departments that fail to adopt the model policy, and eyewitness identifications based on less than model procedures would be allowed into evidence. Still, Lehmberg says, the new law will help Texas take “actual steps forward” to reduce wrongful identifications.
Acevedo agreed that a double-blind system is key to ensuring an unbiased lineup. “I think that there is no debate that the double-blind process is the best procedure,” he said. The APD has updated its internal policy covering police lineups and now has a strict policy built on evidence-based practices – an improvement over its previous policy, which a 2008 report deemed inadequate to protect against faulty identification. Police officers are often resistant to change, Acevedo noted, and strong departmental leadership is key to ensuring that best policies are followed and that consequences for failing to meet that standard are clear and certain. “Once the play is called, we expect our folks to run it,” he said.
The new study was a collaborative effort, involving the American Judicature Society, the Police Foundation, the Innocence Project, and the Center for Problem-Oriented Policing. The Police Foundation will lead a second phase of research, which in part will look at whether the strength of eyewitness evidence affects the strength of other, nonwitness evidence in individual cases.
“A Test of the Simultaneous vs. Sequential Lineup Methods” is posted here.
This article appears in September 23 • 2011.