London police tout success of FRT, flout rules on use of custody images

Police in London have arrested a total of 540 individuals this year using live facial recognition for offenses ranging from shoplifting to rape. Despite these results, the force is facing criticism over the use of technology from local councilors, rights groups – and the country’s biometrics commissioner.

Metropolitan Police published its live facial recognition results last Friday, noting that more than 50 people were involved in serious offenses, including violence against women as well as 50 sex offenders. Over 400 of the arrested individuals have already been charged or cautioned.

“It is a powerful tool that supports officers to identify and focus on people who present the highest risk that may otherwise have gone undetected,” says Lindsey Chiswick, the Met Police director of performance.

Live facial recognition is currently deployed across the UK capital across designated areas using vans equipped with cameras and algorithms developed by NEC. The city authorities allocated £500,000 (US$638,700) for four mobile facial recognition vans as part of a knife crime prevention program in May.

The system captures live footage of passers-by and matches them against a pre-approved watchlist. Facial scans are assigned a similarity score with those above 0.64 indicating a likely suspect. During 2024, facial recognition was used 160 times for more than 800 hours, an analysis of the Met Police figures published by The Telegraph shows. 

An alert from the system does not automatically result in arrest leaving the decision to officers who conduct further checks. At the same time, the algorithm pixelates faces that are not on the watch list and the data is deleted.

Met police faces skepticism from city councilors

The Met Police says that it has implemented robust safeguards for its use of live facial recognition. But the force is still facing skepticism in many of the city’s neighborhoods.

In July, Islington Borough Council rejected the Met Police’s use of live facial recognition, becoming the third council in London to do so after Haringey and Newham. The southeast London area of Lewisham may be next.

The force has claimed that they seek support from residents and local councilors in areas where the technology is being deployed. Levisham councilors, however, have complained about the lack of engagement from the police.

According to a community impact assessment (CIA) obtained by Computer Weekly under freedom of information (FOI) rules, police live facial recognition has been met with mixed opinions while elected officials have expressed concerns. 

“Policing is touted as being legitimized by community consent, so they tick the box of community consultation, but it doesn’t take much digging to find that the consultation is extremely poor,” independent councilor Hau-Yu Tam told the media outlet.

The Met Police responded that the live facial recognition deployments have been supported by the majority of Lewisham residents, business owners and councilors.

The Police Force is also battling on other fronts, including a legal challenge from digital privacy group Big Border Watch over a case of misidentification by the system. In November, UK policing minister Diana Johnston announced a series of discussions on police use of live facial recognition before the end of the year, inviting regulators and civil society groups to share their views.

Commissioner warns about mismanaged police databases

Another challenge to police use of facial recognition comes from the UK’s ­biometrics and surveillance camera commissioner office.

In its annual report, published last week, the commissioner warns that the police are still storing images of innocent people in its national database which may be used for facial recognition checks.

“Forces continue to retain and use images of people who, while having been arrested, have never subsequently been charged or summonsed,” the commissioner says. This is despite a high court ruling in 2012 that keeping custody images of people who faced no charge or were charged and then acquitted was unlawful.

In March, the Scottish Biometrics Commissioner stated that no one is quite sure of the total volume of biometric facial images held by UK police.

London police have been using facial recognition since 2016. The technology has seen a rise in deployment with almost 771,000 faces scanned during the last five years, according to data compiled by the London City Hall Greens party. This summer, the UK government led by Prime Minister Keir Starmer doubled down on deployments of retrospective facial recognition to curb far-right riots in the wake of the Southport stabbings.

Article Topics

biometric identification  |  biometrics  |  Biometrics and Surveillance Camera Commissioner  |  facial recognition  |  London Metropolitan Police  |  police  |  real-time biometrics  |  UK