Are experienced CCTV operators better than naive participants at judging from an unfolding scene on CCTV whether or not a crime is about to be committed? The short answer is no, they aren’t. Presented with 24 real-life 15-second CCTV clips, and asked to predict which half ended just before a crime was about to be committed (examples included violence and vandalism) and which half were innocuous, 12 experienced CCTV operators managed just 55.5 per cent accuracy - no better than if they’d just been guessing. Twelve naive controls achieved an accuracy of just 46.5 per cent - no worse, in terms of statistical significance, than the CCTV operators.
The key to successful predictions seemed to be to pay attention to the social context. Specifically, when participants spent more time focused on the face or head of single individuals not engaged in any social interaction, or looking at the bodies of those in a social interaction, they tended to more accurately predict whether a crime was about to occur. Grant and Williams think this might be because the former allowed the participants to notice when a lone person in the scene was staring at other people, which could betray their plans to commit a criminal act. Meanwhile, viewing the bodies, rather than faces, of those in a social interaction, might have allowed the participants to notice aggressive body language and the spatial proximity of people in a group.



