Visualization of the three lineup procedures. Illustrations of the (A) simultaneous photo lineup, (B) simultaneous interactive lineup, and (C) sequential video lineup. Adapted from https://doi.org/10.1073/pnas.2301845120
In the United States, it is estimated that between 4 to 6 percent of those incarcerated did not commit the crimes they are serving time for. Assuming this rate, that would mean for every 20 people found guilty, one is wrongfully convicted.
According to studies by the Innocence Project, eyewitness misidentification is the leading cause of known wrongful conviction, contributing to approximately 70 percent of known wrongful convictions that have been overturned by DNA testing.
Now, what if there was a way to significantly improve eyewitness identification accuracy? Researchers at the University of Birmingham say there is—by leveraging technology that allows eyewitnesses to dynamically explore digital faces using a new interactive procedure.
These interactive lineups present digital 3D faces that witnesses can rotate and view from different angles using a computer mouse, enabling witnesses to actively explore and match faces to their recollection.
In a study of the new technology, lead author and PhD student Marlene Meyer said witnesses were much better at telling innocent from guilty suspects using the interactive lineups compared with the standard.
Current technology
The current technology used to conduct identifications has not fundamentally changed over the past century. The static 2D photo lineup is the most widely used procedure worldwide. A lineup contains the police suspect, who may be guilty or innocent, and several fillers, who physically resemble the suspect and are known to be innocent of the crime. The members are presented head-on, in frontal view. Witnesses in experiments make mistakes around half the time, and in real-world cases frequently identify known-innocent suspects.
Previous studies have compared sequential to simultaneous lineups, where witnesses view the members one at a time versus all together. Laboratory research has also examined video lineups, which are used in the U.K. and presented sequentially, with each member turning their head left and right to show the faces from every angle.
Thus far, the studies have been inconclusive, with some finding discriminability higher in simultaneous lineups, while others have found witnesses’ response bias is more lenient in simultaneous lineups, resulting in more guilty and innocent suspect identifications.
“In this study, we heed the National Academy of Sciences call for technology to improve discriminability and investigate whether enabling witnesses to actively explore the members’ faces along the vertical axis from −90° to 90° improves discriminability compared to sequential video and simultaneous photo lineups, the two most widely used procedures worldwide,” explain the study authors.
New technology
In the study recently published in PNAS, researchers recruited 550 volunteer witnesses to test their ability to make a correct identification of previously seen individuals. Participants encoded 12 target faces, either from the front or in profile view, and then attempted to identify the targets from 12 lineups, half of which has the “target” present, half of which did not.
The volunteer witnesses were randomly assigned to one of three lineup conditions: simultaneous interactive, simultaneous photo, or sequential video.
According to the study results, discriminability was higher in interactive compared to both photo and video lineups. In fact, the researchers found that presenting the images via interactive lineups improved accuracy by 27 to 35% over photo arrays, and 35 to 75% over video lineups.
“Signal-detection modeling in the study suggests interactive lineups increase discriminability because they afford the witness the opportunity to view more diagnostic features such that the nondiagnostic features play a proportionally lesser role,” explain the study authors.
The study is the first to experimentally compare interactive lineups against police video lineups and photo arrays.
“By integrating this technology, we may observe a dramatic reduction in identification errors, which will pave the way toward more just outcomes in criminal investigations and proceedings around the world. This tech update to police procedures warrants further testing and adoption to prevent wrongful convictions,” said senior author Heather Flowe at the University of Birmingham.