On the last day of the 2005 term, the Wisconsin Supreme Court handed down a decision that incorporates modern scientific research on eyewitness identification, and, in the process, does a great deal to reduce the risk of wrongful conviction.
In Dubose, the Court held that eyewitness evidence obtained through use of a show-up is inadmissible unless conducting a show-up was necessary. 2005 WI 126. Show-ups will be deemed unnecessary unless police lacked probable cause to arrest or other exigent circumstances prevented conducting a lineup or photo array.
A show-up occurs when police present one suspect to one witness for the purpose of making an eyewitness identification. Courts have long recognized that show-ups are suggestive. An eyewitness viewing a show-up can safely assume that the police have some good reason to believe the suspect is the perpetrator. Furthermore, unlike in a lineup or photo array, a witness viewing a show-up is not forced to recognize the perpetrator from an array of fillers who fit the perpetrator's general description. For these reasons, social science research reveals that show-ups produce a greater risk of mis-identification than lineups or photo arrays.
Despite the suggestiveness inherent in show-ups, courts have traditionally allowed show-up evidence to be admitted except in the most egregious circumstances. In Dubose, the Wisconsin Supreme Court broke with that tradition, holding that show-up evidence is admissible only if the prosecution can demonstrate that conducting a show-up was necessary. Under the Court's new rule, not only is it difficult for the state to prove the necessity of conducting a show-up, but show-up evidence may also be excluded if police fail to utilize procedures designed to minimize the inherent suggestiveness of show-ups. For example, police procedures such as failing to instruct the witness that the person presented may not be the perpetrator, or unnecessarily conducting the show-up while the suspect is restrained in a squad car, may result in suppression of the show-up evidence.
The Wisconsin Innocence Project filed an amicus brief in the case.