The Influence of Threat Situation and Expectation on the Weapon Focus Effect in a Virtual Mock-Crime Video

This study aimed to investigate whether the eyewitness expecting to see a weapon would cause the weapon focus effect (WFE) in the threat or non-threat situation. Two video clips showing the presence or absence of a threat (crime or refund) were used. 80 participants were randomized within four conditions: threat and expected, threat and enexpected, non-threat and expected, and non-threat and unexpected. The expected group was provided with critical information about the incident before watching the video clip, while the unexpected group was not. To identify the occurrence of the WFE, eye-movement was measured while the participants were watching the interaction between two individuals in a crime scene or a refund scene; then, a memory recall test and a photo line-up test were conducted at the end of the experiment. Our results indicate that the threat and unexpected condition showed a significantly longer dwell time on the weapon than did other conditions. Therefore, our results suggest that participants’ expectancy to see a weapon can be reduced in the WFE, but the threatening situation will still cause the WFE.