The Metropolitan Police Service in London is to employ facial recognition on Christmas shoppers in Westminster on 17 and 18 December as part of an ongoing trial of the technology. The Met Police has said the tests will run for eight hours each day.
The deployment will cover areas in Soho, Piccadilly Circus and Leicester Square.
The technology is being used in Westminster as part of the Met's ongoing efforts to reduce crime in the area, with a specific focus on tackling violence. All the faces on the database to be used during the deployment are of people wanted by the Met and the courts.
Anyone who declines to be scanned during the deployment will not be viewed as suspicious by police officers.
If the technology generates an alert of a match, police officers on the ground will review it and further checks will be carried out to confirm the identity of the individual.
The strategic lead for live facial technology for the MPS, Ivan Balhatchet, said: "The Met is currently developing the use of live facial recognition technology and we have committed to ten trials during the coming months. We are now coming to the end of our trials when a full evaluation will be completed."