At 11.12am last Tuesday, a woman in her 70s sauntered through the main entrance of the Ruxley Manor garden centre in Sidcup, south-east London. Upstairs in its offices, the phone of director James Evans pinged.
Facial recognition cameras had identified the pensioner as a potential criminal. Two weeks earlier, she had been caught stealing £15 worth of toys for her granddaughter and her image uploaded on to a private watchlist of known shoplifters.
