Three people were arrested in London this week as a direct result of live facial recognition technology that is being trialled by police.
The controversial surveillance software was deployed in Romford, east London on Thursday as part of a wider trial in the British capital.
It identified suspects wanted for offences including kidnapping and breach of a molestation order.
A 15-year-old suspect arrested on suspicion of robbery as a result of the technology was later assessed as "no longer wanted" and released.
“The technology used in Romford forms part of the Met's ongoing efforts to reduce crime in the area, with a specific focus on tackling violence,” Commander Ivan Balhatchet said in a statement.
However, critics say facial recognition technology is not the answer.
Privacy campaign group Big Brother Watch claimed that several people were stopped by police in Romford for covering their faces.
The group has described the technology as “lawless and intrusive” and says it risks turning the public into “walking ID cards”.