Digital Detectives: Websleuthing Reduces Eyewitness Identification Accuracy in Police Lineups

Abstract

Eyewitnesses to crimes sometimes search for a culprit on social media before viewing a police lineup, but it is not known whether this affects subsequent lineup identification accuracy. The present online study was conducted to address this. Two hundred and eighty-five participants viewed a mock crime video, and after a 15–20 min delay either (i) viewed a mock social media site including the culprit, (ii) viewed a mock social media site including a lookalike, or (iii) completed a filler task. A week later, participants made an identification from a photo lineup. It was predicted that searching for a culprit on social media containing the lookalike (rather than the culprit) would reduce lineup identification accuracy. There was a significant association between social media exposure and lineup accuracy for the Target Present lineup (30% more of the participants who saw the lookalike on social media failed to positively identify the culprit than participants in the other conditions), but for the Target Absent lineup (which also included the lookalike) there was no significant association with lineup identification accuracy. The results suggest that if an eyewitness sees a lookalike (where they are expecting to see the culprit) when conducting a self-directed search on social media, they are less likely to subsequently identify the culprit in the formal ID procedure.

The impact of viewing social media images on eyewitness identification.

“…In the preregistration, there was an error in the directionality of the perpetrator-present hypothesis. Our intent was to hypothesize that, consistent with previous research(Elphick et al, 2021;Kleider-Offutt et al, 2022), correct identifications would be lower in the social media and mugbook conditions than in the control condition. However, the preregistration mistakenly includes a prediction that correct identifications would be higher in the social media and mugbook conditions than in the control condition.…”

“…In one study, viewing an innocent suspect on Twitter significantly increased mistaken identifications of the innocent suspect at a subsequent lineup (Kleider-Offutt et al, 2022). In two additional studies, mistaken lineup identifications of innocent suspects also increased after viewing them on social media (25% increase in Elphick et al, 2021;15% increase in Havard et al, 2023). Although the increases were not significant relative to controls in the latter two studies, the trends are consistent with the expectation that viewing images of an innocent suspect on social media would have the same contaminating effect as viewing mugshots.…”

“…In two experiments, we tested whether the mutual friends feature on social media would be suggestive of a potential suspect and cause even greater memory contamination than mugshot exposure. Based on the existing research on social media identifications (Elphick et al, 2021; Havard et al, 2023; Kleider-Offutt et al, 2022), there is no evidence that social media exposure affects identification decisions any differently than mugshot exposure does. However, social media and mugshot viewings were not directly compared in any of the previously published experiments.…”

“…Perhaps most analogous to social media searches is the mugshot exposure effect, which is when eyewitnesses who have previously viewed a mugshot of an innocent suspect are more likely to mistakenly identify the suspect at a subsequent lineup procedure (Brown et al, 1977; Deffenbacher et al, 2006). Recent research suggests that searching social media can have similar effects (Elphick et al, 2021; Havard et al, 2023; Kleider-Offutt et al, 2022), but the relative risks posed by social media and mugshot images have never been directly compared. In the present research, we report two experiments examining whether a common feature of social media—the mutual friends indicator—has the potential to cause an even greater risk of misidentification for an innocent suspect.…”

Composite communication: how dissemination of facial composites in the media affects police investigations

“…Furthermore, a phenomenon called ‘websleuthing’ has emerged (Yardley et al 2018), which involves citizen detectives conducting elaborate amateur online investigations to help law enforcement solve crimes, for example, through ‘Facebook identifications’ (Brice 2013). On a smaller scale, eyewitnesses to crimes may search social media to see if they can find the perpetrator (Elphick et al 2021; Havard et al 2021). If such a social media search leads them to a person whom they recognise – rightly or wrongly – as the person who committed the crime, exposure to photos of this person is likely to alter the eyewitness's original memory for the perpetrator, as we will explain in further detail later in this chapter.…”