Live facial recognition is being hailed as a powerful new frontier in the fight against crime, not only by police but by private companies too. Retailers from supermarkets to corner shops hope it will help them fight back against shoplifting.

But the Guardian’s social affairs correspondent, Jessica Murray, points out that it will also expand surveillance into more and more public spaces. And the technology doesn’t always get it right.

She tells Annie Kelly about shoppers who were wrongly accused by an AI system of breaking the law and found it surprisingly difficult to set the record straight. With more police forces wanting to take up the technology, what could the consequences be?