Live Facial Recognition

Live facial recognition scans the faces of everyone passing a camera, converts each to a biometric template, and compares it in real time against a watchlist. Where the system alerts, an officer reviews the match and decides whether to intervene. Faces that do not match are, forces state, deleted immediately and automatically.

It is the most contested technology in this catalogue, and in the United Kingdom it now operates at scale with judicial approval and no dedicated statute.

WHAT THE UK COURTS HAVE DECIDED

Two judgments frame current UK practice.

Bridges v Chief Constable of South Wales Police (Court of Appeal, 2020) found aspects of that force's deployment unlawful. It did not ban the technology. It required forces to tighten policies, address the public sector equality duty and engage with data protection law — while considering the broader context including potential racial bias and retention of innocent people's data.

Thompson v Metropolitan Police, decided 21 April 2026 by Lord Justice Holgate and Mrs Justice Farbey, is the first substantive test of what Bridges meant in practice. Shaun Thompson, a youth worker with an anti-knife-crime charity, was stopped outside London Bridge station in February 2024 after the system matched him — according to the court's media summary — against his brother, who was on a watchlist. Told he was "a wanted man", he asked what for and was told that was what officers were there to find out. His bank cards and passport did not resolve it; he refused to give fingerprints. He has described the experience as "stop and search on steroids".

Thompson and Big Brother Watch director Silkie Carlo, supported by the Equality and Human Rights Commission, did not argue that live facial recognition is unlawful in principle. Their argument was narrower and more structural: that the Met's policy leaves too much discretion to officers over where, why and against whom the technology is used.

The court dismissed the challenge, finding the Met's policy contains "clear, interlocking and cumulative constraints", and that the risk of racial discrimination was "no more than faintly asserted". Notably, it declined to consider hypotheticals, confining itself to the Met's actual policy. Thompson is appealing.

THE STRUCTURAL POINT THAT FOLLOWS

What the court reviewed was a police force's own policy document. There is no UK statute governing live facial recognition. The lawfulness of the largest deployment in Europe currently rests on the adequacy of rules the deploying force wrote for itself, assessed by a court that expressly declined to consider circumstances other than those before it.

That is the single most important thing to understand about UK live facial recognition, and it holds regardless of one's view of the technology.

THE MET'S NUMBERS

Figures come from different periods and are easy to conflate, so they are separated here.

By April 2026 the Met reported more than 2,100 arrests since the start of 2024, around a quarter involving violence against women and girls, and more than 100 sex offenders. Over the preceding year it reported more than three million faces scanned producing 12 false alerts, none of which led to an arrest, with every alert reviewed by a trained officer before action.

For September 2024 to September 2025 specifically, the force reported 962 arrests, and 10 false alerts. Of those ten people, eight were Black. Four were not stopped; the rest were spoken to for under five minutes. An earlier report recorded more than 1,400 arrests in total with over 1,000 charged or cautioned.

A six-month static deployment in Croydon produced 173 arrests.

Commissioner Sir Mark Rowley called the judgment "a significant and important victory for public safety", and has said the question is no longer whether to use the technology but why a force would choose not to. A Mayor's Office survey found 85% of respondents backed use to locate serious and violent criminals and those wanted by the courts.

THE CASE FOR IT

The arrest figures are substantial and the offence mix is not trivial: rape, strangulation, domestic abuse, child sexual offences, and offenders in breach of court-imposed conditions. These are people the Met says would otherwise have gone undetected.

The false alert rate, as the Met presents it, is genuinely low. Twelve false alerts against three million faces, none producing an arrest, is a better real-world error rate than most predictions about this technology assumed. Human review of every alert is a meaningful control and appears to be working as designed.

Public support, on the polling available, is high.

THE CASE AGAINST

The eight-of-ten figure deserves attention precisely because the Met published it. Ten false alerts is a small sample and no strong statistical inference can be drawn from it — but of the people wrongly flagged in that year, eight were Black, and that is the disparity the NPL threshold testing predicts at lower confidence settings. It sits uncomfortably with a court finding that discrimination risk was "faintly asserted".

The denominator argument cuts both ways. Three million faces scanned is presented as evidence of accuracy; it is also three million people whose biometrics were captured without suspicion, consent or any individualised justification. Counsel for Thompson argued that facial recognition data is comparable to a DNA profile, and that permanent installations would make it impossible for Londoners to move without routine biometric capture.

Thompson's own account illustrates what a low error rate means for the person inside it. He was compliant, carried identity documents, and still could not persuade officers the machine was wrong. That inversion — where documentary evidence is weighed against an algorithmic assertion — is the practical harm, and it is not captured by any accuracy statistic.

Nor is he isolated. A software engineer has announced plans to sue Thames Valley Police after being confused with a burglar.

Expansion is proceeding regardless of the appeal. The Home Office announced 40 additional LFR vans, taking national deployment from around 10 to 50 across England and Wales.

WHAT IS NOT ESTABLISHED

Whether false alert figures are compiled consistently across forces, and whether a person spoken to but not arrested is counted, is not clear from published material.

Ethnicity data for false alerts is not routinely published by all forces, so the Met's disclosure cannot be compared nationally.

No published figure was found for how many of the 2,100 arrests resulted in charge, conviction, or a disposal that would not have occurred otherwise.

The outcome of Thompson's appeal is pending, and the Home Office consultation response on a facial recognition framework remained unpublished well past its due date as of August 2026.