“Eyewitness misidentification is the single greatest cause of wrongful convictions nationwide, playing a role in more than 75 percent of convictions overturned through DNA testing.”

The Innocence Project, a national organization that works to exonerate those who have been wrongly convicted, released this information. The Innocence Project also works to reform the justice system, and that’s where Gary Wells, an ISU distinguished professor of psychology, comes in.

Wells has been working on a procedure to help eyewitnesses make more accurate identifications for nearly 30 years. This method, known as the sequential procedure, shows witnesses one photo at a time, compared to the simultaneous method that shows multiple photos at once.

The study was conducted with the use of a laptop, using specific software, giving the witness instructions and then randomly selecting the use of the sequential or simultaneous procedure. In each procedure, there was one suspect, or person known to be guilty through the experiment, and five fillers, or persons known to be innocent.

In the sequential procedure, witnesses were shown one picture at a time.

The witness had to choose if the person shown was or was not the suspect before proceeding to the next picture. They also gave all of their answers verbally, which was recorded by the laptop. In the simultaneous method, witnesses were shown all of the pictures at once and then asked to verbally make a selection.

According to the results released by the American Judicature Society, an organization that works to protect the honor of our justice system, in the simultaneous procedure witnesses correctly identified the suspect 25.5 percent of the time. In the sequential procedure, witnesses correctly identified the suspect 27.3 percent of the time. This is considered “not statistically significant.”

However, the same report also showed that the choosing of a filler, or innocent person, in the simultaneous procedure occurred in 18.1 percent of the identifications compared to the 12.2 percent with the sequential procedure. This is considered, “a statistically significant difference.”

“This shows how often witnesses are clearly making an error,” Wells said. “I think this study will help show those with reservations that this method is a true improvement.”

Those “reservations” come from police departments that feel that the studies are unreliable because the people used are not real eyewitnesses to serious crimes. “They believe real witnesses would be too cautious to make errors,” Wells said.

To solve this issue, the study was conducted with the help of four separate police departments in Charlotte-Mecklenburg, N.C., Tucson, Ariz., San Diego, Calif., and Austin, Texas. At these locations, witnesses did not know that they were taking part in a study.

“We want to try to get police departments on board to change their procedures … make [eyewitness identifications] more reliable,” said Danielle Mitchell, project manager of the American Judicature Society Center of Forensic Science and Public Policy.

Wells hopes to continue his research by looking at “how certain the witness was on their own at the time they make the identification.” This will be done by listening to the audio recordings, studying the certainty of the answer given by each witness and comparing it to if the witness did or did not select the correct suspect.

Race, quality of view when witnessing the crime, amount of time passed between the crime and the time of identification, and if a weapon was involved, also will be researched in the future studies.