Should Police Use Facial Recognition Technology?

Posed as a flat yes-or-no, the question almost answers itself, but the serious version is sharper. The police already use facial recognition; the real issue is on what terms. I will argue that they should be permitted to use it, but only inside a binding legal framework that bars live, indiscriminate scanning of the public save for narrow, court-authorised exceptions, while allowing tightly governed retrospective searches. Unregulated deployment, of the kind British courts have already condemned, is indefensible.

The case for permitting the technology at all is genuine and should not be caricatured. Used after the event against a known image, facial recognition can identify suspects in terrorism, trafficking and serious violence far faster than officers combing footage by hand. Even the European Union's AI Act, which prohibits most live public use, deliberately preserves exceptions for finding trafficking victims, locating missing people and stopping imminent terror attacks. A blanket ban would also forbid these narrow, warranted searches, depriving investigators of a tool no more intrusive in principle than the fingerprint and DNA databases the law already sanctions under controls. To abolish the capability outright is to overcorrect.

Live scanning of crowds, however, is a different animal. An ordinary camera records; facial recognition identifies. It converts every passing face into a database query, scalable, searchable and persistent, and so amplifies state power rather than merely extending an existing one. This is why, in R (Bridges) v Chief Constable of South Wales Police, the Court of Appeal held that the force's live deployment engaged Article 8 of the Convention and was unlawful, not because the aim was illegitimate but because the rules left too much to officers' discretion over who went on a watchlist and where the cameras were pointed. The court also found breaches of the Data Protection Act 2018 and the public sector equality duty. The lesson is precise: the problem was the absence of a clear, specific framework, exactly what regulation would supply.

The technology's flaws sharpen the point. The United States' National Institute of Standards and Technology, testing nearly two hundred algorithms, found false-positive rates for Asian and African American faces in one-to-one matching ten to a hundred times higher than for white faces, with the worst one-to-many error rates falling on Black women. These are not abstract differentials. Because officers tend to trust a computer 'match', a probabilistic hint hardens into a custodial fact, as Robert Williams discovered in Detroit, wrongly arrested on a false match and held for thirty hours in front of his family. Equality before the algorithm is part of equality before the law, and only mandated accuracy thresholds, bias audits and human-in-the-loop rules can deliver it.

There is a further, democratic cost. People behave differently when they know every face is logged; live recognition outside a protest or a place of worship deters the lawful assembly and expression protected by Articles 10 and 11, and function creep tends to drag such tools from serious crime toward routine monitoring. A democracy that cannot tolerate anonymity in a crowd has surrendered something essential. Nor can deployment be left to internal policy, since the decisive judgments ride on proprietary algorithms shielded as trade secrets; without compulsory impact assessments, logging and independent audit, neither courts nor defendants can test reliability or exclude tainted evidence. Self-policing by the forces that benefit is not oversight.

The answer, then, is a regulated yes. A tiered statutory regime, of the sort the House of Lords Justice and Home Affairs Committee urged and the EU AI Act roughly models, should prohibit live mass identification except under prior judicial authorisation for imminent serious offences, permit retrospective searches only on high thresholds with a documented impact assessment, and require independent accuracy certification, retention limits, notice and redress. Far from hamstringing the police, clear rules make lawful use predictable and unlawful use contestable, and turn scattered pilots into a system that evidence can rest on.

So the police should use facial recognition, but only on terms set by binding law. Without that framework we invite illegality, wrongful arrest and democratic chill; with it, we keep a targeted tool while protecting the rights it threatens. The question is not whether, but how, and the honest how is regulation.