The Weapon Focus Effect in Target‐Present and Target‐Absent Line‐Ups: The Roles of Threat, Novelty, and Timing

Abstract

SummaryWhen an eyewitness suffers an impairment of memory for a perpetrator because the criminal used a weapon during the crime, this impairment is called the weapon focus effect. The literature is split on how this arises: Some implicate the narrowing of attentional cues to the weapon because the arousal of the victim increases, whereas others claim that the weapon is a novel object in most everyday contexts, and novel objects demand more attention than contextually appropriate ones. The current study employed a simulated crime paradigm featuring a normal, novel, or threatening object. Timing of the object's presentation was manipulated such that it was visible before, after, or during the time when the culprit's face was visible. Target‐present and target‐absent line‐ups as well as retrospective questions were administered. Both the novel object and the weapon resulted in increased mistaken identifications in target‐absent line‐ups. Structural equation modeling suggested that object novelty mediated this effect. Copyright © 2014 John Wiley & Sons, Ltd.

The Influence of Arousal and Expectation on Eyewitness Memory in a Virtual Environment

“…These results are consistent with previous studies that have shown a negative effect of an unexpected event on EM. 18,19,26,27 The present study has some limitations. First, we measured emotional arousal using self-reporting measures.…”

The Influence of Perpetrator Exposure Time and Weapon Presence/Timing on Eyewitness Confidence and Accuracy

“…Historically, the effect on eyewitness identification has been less robust (e.g., Kramer et al, ; see meta‐analysis by Fawcett, Russell, Peace, & Christie, ). However, four experiments have recently found that eyewitness identification accuracy does indeed decline for crimes involving a weapon (Carlson & Carlson, , ; Carlson, Dias, Weatherford, & Carlson, in press; Erickson, Lampinen, & Leding, ). Two of these will be discussed in greater detail below.…”

“…Erickson et al () addressed many of these limitations (see also Carlson & Carlson, , ). They conducted a large ( N = 1263; about 70/cell) experiment involving the timing of a neutral object (empty glass), unusual object (rubber chicken), or weapon (fake but realistic‐looking gun) during a slide presentation.…”

“…We sought to continue in the spirit of Erickson et al () by conducting a well‐powered study including all relevant conditions in one experimental design for the sake of easier comparison among conditions. We also addressed limitations present in either Kramer et al () or Erickson et al First, Erickson et al presented the lineup immediately after their slides.…”

The influence of alcohol and weapon presence on eyewitness memory and confidence

“…However, the strongest evidence of weapon focus is confined to laboratory studies in which participants are shown a mock‐crime (either live or via video or slideshow) that they are later questioned about. Participants who witness a scene featuring an armed perpetrator tend to remember this person less accurately than those shown a matched scene in which he was unarmed (e.g., Carlson, Dias, Weatherford, & Carlson, ; Cutler, Penrod, O'Rourke, & Martens, ; Cutler, Penrod, & Martens, , ; Erickson, Lampinen, & Leding, ; Loftus et al, , Experiment 2; Pickel, ; Tooley, Brigham, Maass, & Bothwell, ). Although there is evidence that arousing stimulus scenes restrict the attentional focus of participants on to the most central features impairing memory for peripheral scene features (Christianson, ; Davies, Smith, & Blincoe, ), it is unlikely that the levels of participant arousal elicited by mock crimes shown in lab studies are anywhere near as high as those experienced by witnesses of real armed crimes (Kocab & Sporer, ).…”