“It’s about identification and verification of people that would generally be stopped on a particular purpose,” said Mr Field.
“It could be ranging from missing people, vulnerable people such as someone suffering from Alzheimer’s, to children. It could be people banned from particular events such as football stadiums.
“If there was a new crime or a range of suspects and you sent a policeman to interview people, it would be one way of increasing your chances of identifying someone.”
However, he added: “I don’t want mass surveillance and I don’t want my kids to inherit a world where you know you’re going to be spied on. That is not what I’m trying to do in any way.”
There have been concerns about the accuracy and potential bias of facial recognition technology, but Mr Field said the software had been tested on thousands of faces and there had not yet been any false positives.
Privacy campaigners, however, warned that the use of the technology risked creating an “Orwellian police line-up”.
“This could turn innocent citizens’ encounters with the police, whether on the roads, at general call-outs or demonstrations, into an Orwellian police line-up,” said Silkie Carlo, director of civil liberties group Big Brother Watch.
“Live facial recognition obliterates privacy and there are eye-watering possibilities for abuse. An urgent moratorium on authorities’ use of live facial recognition is needed. This deeply flawed spying technology has no place being sold or used in the UK.”
Official codes covering the deployment and use of facial recognition are being tightened after South Wales Police’s use of such cameras was judged unlawful, after a court action by an innocent member of the public who was filmed and who complained about breaches of his privacy.
