Identification from CCTV: Assessing police super‐recogniser ability to spot faces in a crowd and susceptibility to change blindness

Abstract

Police worldwide regularly review closed-circuit television (CCTV) evidence in investigations. This research found that London police experts who work in a full-time "Super-Recogniser Unit" and front line police identifiers regularly making suspect identifications from CCTV possessed superior unfamiliar face recognition ability and, with higher levels of confidence, outperformed controls at locating actors in a bespoke Spot the Face in a Crowd Test. Police were also less susceptible to change blindness errors and possessed higher levels of conscientiousness and lower levels of neuroticism and openness. Controls who took part in Spot the Face in a Crowd Test actor familiarisation training outperformed untrained controls, suggesting this exercise might enhance identification of persons of interest in real investigations. This research supports an accumulating body of evidence demonstrating that international police forces may benefit from deploying officers with superior face recognition ability to roles such as CCTV review, as these officers may be the most likely to identify persons of interest.

TooManyEyes: super-recogniser directed identification of target individuals on CCTV

“…As expected, consistent with previous research [15], police who have experience of working in a full time Metropolitan Police Service (MPS) CCTV review SuperRecogniser (SR) Unit, some of whom may possess exceptional face recognition ability, significantly outperformed police controls in terms of higher rates of correct identifications of target-actors depicted in the SFCT. SRs' confidence in correct identifications was also significantly higher than controls, again supporting predictions and in line with previous research [15]. However, probably due to low statistical power, from low participant numbers, no differences were found in rates of false bystander identifications (false positives) or correct rejections of empty clips, although the scores were in the expected direction.…”

“…The abridged version of the SFCT consisted of six video clips (the original version [15] had 11 clips) in which four target-actors walking through the environment were depicted in four of the clips. Two clips were empty of targets, and one target appeared in two clips.…”

“…Recent research [15], testing full-time SRs from the MPS SR Unit in London (n = 7), other police (n = 92) and controls drawn from the public (n = 152) found positive relationships between performances on an early version of the SFCT, the extended version of the Cambridge Face Memory Test (CFMT+) [5], used in most previous research to allocate SRs to SR groups [e.g., [1][2][3][4][5], and a Change Blindness test [16]. As a group, members of the MPS SR Unit outperformed the other groups on the three tests, although not all achieved SR criteria used in previous research.…”

“…However, CCTV review operations require alternative skills such as vigilance and close attention to detail that not all SRs may possess. Therefore, SR police have been tested on a Spot the Face in the Crowd Test (SFCT), where they have to search for unfamiliar target actors playing 'missing persons' in footage depicting crowds of bystanders [15]. The SFCT replicates a CCTV review task and draws on facial memory and simultaneous unfamiliar face matching, as well as concentration, vigilance, and attention on the task in hand -skills not assessed in typical face recognition and matching tests.…”

Searching for faces in crowd chokepoint videos

“…As the number of actors that participants were required to search for increased, overall performance on the SFCT decreased (Davis et al, ). For instance, the mean proportion of hits fell from .77 (two actors) to .59 (eight actors), whereas the mean proportion of correct rejections (.66 and .68 respectively) remained unchanged.…”