Eyewitness Identification and the Weapon Focus Effect: Effects of Weapon Presence, Concealment and Exposure Time


Jennifer Dias

Document Type


Degree Name

Doctor of Philosophy (Ph.D)


Educational Psychology

Date of Award

Spring 2017


The study examined the effect of exposure to the perpetrator and weapon visibility on the weapon focus effect (WFE). Participants were presented a mock crime video with the perpetrator holding either no weapon, a visible weapon, or a concealed weapon which he refers to and creates a bulge in his clothing. One exposure condition exposed the witness to the perpetrator and weapon for approximately 25 s and another for approximately 35 s from a distance of 2-4 m. After watching the video, participants were asked to make an identification decision from either a perpetrator-present or -absent lineup and rate their confidence in that decision. The first prediction was that the WFE would be replicated in the bad, but not good view of the perpetrator. A second prediction was there would be no WFE in the concealed condition for either good or bad view of the perpetrator. A final prediction was that those presented with the good view of the perpetrator would out-perform those presented with the bad view, regardless of weapon presence. Participants with a bad view of the perpetrator were more likely to falsely identify a foil from a perpetrator-absent lineup. Unexpectedly, the visible weapon condition produced fewer correct identifications than concealed and no weapon conditions. Accuracy was highest in the concealed and visible weapon conditions.


Curt Carlson

Subject Categories

Education | Educational Psychology