In 1998 i was part of a project team that included the Met Police’s IT R&D team. Those guys had a novel facial recognition system then, that was trialled in Clarendon Road in Watford. The results were not good, but the reason for canning it was that the civil liberties groups were going nuts and threatening mayhem. I cannot believe that 26 years later they haven’t already implemented it and been using it for some time.