Eyewitness Identification and the Weapon Focus Effect: Influence of Schema Consistency for Objects and Actions

Document Type


Degree Name

Master of Science (MS)


Educational Psychology

Date of Award

Summer 2018


The purpose of this study was to examine the unusualness hypothesis of the weapon focus effect (WFE) by extending it to typical items used in an unusual manner. The WFE occurs when a weapon during a crime attracts a witness’s attention and results in diminished memory for non-weapon aspects of the crime scene, including the perpetrator’s face. I examined the unusualness hypothesis, which purports that the presence of an unusual item in a setting can cause an effect similar to the WFE. In my study, I examined an unusual object, a weapon, and also a typical object used in an unusual manner. Participants viewed a mock-crime video that included a man interacting with either a (a) gun, (b) children’s toy, (c) stapler used as stapler, or (d) stapler used as weapon. Later they attempted to identify him in a lineup. Results indicate that the presence of the gun negatively affected eyewitness identification. The other three conditions did not produce a WFE. Whereas these results support the WFE, they do not support the unusualness hypothesis (at least in terms of eyewitness identification), either for atypical objects or typical objects used in an atypical manner.


Curt A Carlson

Subject Categories

Education | Educational Psychology