NCJ Number
196642
Journal
Law and Human Behavior Volume: 26 Issue: 4 Dated: August 2002 Pages: 439-453
Date Published
August 2002
Length
15 pages
Annotation
This study tested the use of mockwitnesses in lineups during a criminal investigation.
Abstract
Mistaken identifications of innocent people are more likely when the suspect stands out in a lineup. Mockwitnesses are individuals that have not witnessed a crime but are asked to select the individual they think perpetrated the crime from a lineup based on only his/her physical description given by the eyewitness. The rationale is that if a lineup is constructed properly, each member of it should have an equal probability of being selected by individuals that did not witness the crime. This research was designed to examine (1) whether mockwitnesses’ estimates of lineup bias would vary as a function of changes in the standard mockwitness procedure, and (2) the source(s) of mockwitnesses’ identifying information. Over 400 undergraduate students were used as mockwitnesses. The four variables were lineup structure, lineup instructions, criterion instructions, and target. Considering mockwitnesses that made one lineup choice, the data showed that a significant proportion of participants detected structural bias when presented with a biased sequential lineup. For those shown a fair sequential lineup, the identification rate of the target did not significantly differ from that of other lineup members. Manipulations of lineup instructions and criterion instructions had no detectable effect. Interpretation of the data was less clear for participants that made multiple lineup choices. These mockwitnesses identified the target significantly more often than was expected by chance when presented with both fair and unfair lineups. These data show that participants approach the mockwitness task with individual orientations. The instructions and the nature of the mockwitness task appear to orient mockwitnesses to the physical description of the offender as the primary source of identifying information. A notable response given by a few participants was that their own stereotypes or schemas for criminal appearance drove their lineup choice(s). 12 footnotes, 46 references