Landmark legal challenge against police facial recognition begins
A judicial review against the Metropolitan Police’s use of live facial recognition (LFR) will argue the force is unlawfully deploying the technology across London, without effective safeguards or constraints in place to protect people’s human rights from invasive biometric surveillance.
Brought by anti-knife campaigner Shaun Thompson, who was wrongfully identified by the Met’s system and subject to a prolonged stop as a result, and privacy group Big Brother Watch, the challenge will argue there are no meaningful safeguards in place to effectively limit how the Met uses the technology.
In particular, it will argue the Met’s policy on where it can be deployed and who it can be used to target is so permissive and leaves so much discretion to the force that it cannot be considered “in accordance with law”.
“The reason for the ‘who’ requirement is clear,” wrote Thompson and Big Brother Watch in their skeleton argument for the case. “It serves to protect against people being selected for a watchlist for reasons that are arbitrary, discriminatory or without sufficient basis. As to the ‘where’ requirement, the concern is not with the individuals on the watchlist, but the thousands of innocent people who will have their biometric data taken while going about lawful quotidian activities.”
They added that, as with the “who”, similarly constraining officers’ discretion as to “where” LFR can be used inhibits officers from selecting locations for reasons that are arbitrary, discriminatory, or otherwise have an insufficient basis.
“That is a safeguard against individual officers selecting areas arbitrarily or improperly targeting areas where people of certain races or religions disproportionately live or consistently targeting deprived communities in London,” they wrote, adding that if there are insufficient constraints on “where” LFR can be used, it will be impossible for people to travel across London without their biometric data being captured and processed.
“Any public place risks becoming one in which people’s identities are liable to be checked to see if they are of interest to the police,” they continued. “That would be to fundamentally transform public spaces and people’s relationship with the police.”
Rights breaches
Ultimately, Thompson and Big Brother Watch will argue that the Met’s LFR use breaches the rights to privacy, freedom of expression, and freedom of assembly.
This marks the first legal challenge in Europe brought by someone misidentified by facial recognition technology.
After Thompson was wrongly flagged by the technology when travelling through London Bridge, officers detained him while they asked for identity documents, repeatedly demanded fingerprint scans, and inspected him for scars and tattoos.
The police stop continued for over 20 minutes, during which time Thompson was threatened with arrest, despite providing multiple identity documents showing he had been falsely identified.
Thompson, a 39-year-old Black man, described the police’s use of LFR at the time as “stop and search on steroids”.
In August 2020, the Court of Appeal previously found that South Wales Police (SWP) had been deploying LFR unlawfully, on the grounds there were insufficient constraints on the force’s discretion over where LFR could be used, and who could be placed on a watchlist.
“The possibility of being subjected to a digital identity check by police without our consent almost anywhere, at any time, is a serious infringement on our civil liberties that is transforming London,” said Big Brother Watch director Silkie Carlo ahead of the case being heard.
“When used as a mass surveillance tool, live facial recognition reverses the presumption of innocence and destroys any notion of privacy in our capital. This legal challenge is a landmark step towards protecting the public against intrusive monitoring.”
Legal arguments
On where police can deploy LFR, the Met’s policy documents state the force can deploy LFR cameras at “crime hotspots”, including “access routes” to those hotspots; for “protective security operations”, meaning at public events or critical national infrastructure; and locations based on officers’ intelligence about “the likely location [of] … sought persons”.
However, according to their skeleton argument, Thompson and Big Brother Watch will say the policy does “not meaningfully constrain the discretion as to where LFR can be located”.
It added that while these use cases are intended to circumscribe where the tech can be used, a third-party analysis conducted by Martin Utley – a professor of operational research at University College London – suggests that, in practice, “they confer far too broad a discretion on individual officers, and permit them to deploy LFR anywhere they choose in the significant majority, if not the vast majority, of public spaces in the Metropolitan Police District at any time”.
The argument also added that while the Met’s LFR policy permits officers to designate areas as “crime hotspots” based on “operational experience as to future criminality”, this is “opaque and entirely subjective”.
Utley specifically found that an estimated 47% of the Met’s policing district is labelled as a “crime hotspot”, and that LFR could be deployed on access routes that cover a further 38%, rendering 85% of London open to LFR deployments.
A separate analysis conducted by the Met found that LFR can be located in around 40% of the Metropolitan Police District, compared with Utley’s 47%.
Highlighting how SWP’s use of the tech was found unlawful due to the broad discretion conferred to officers in that case, the argument claims that, taken all together, the Met’s deployment use cases mean that “most of the city is covered”.
“There are two ways LFR can be deployed,” it said. “It can be used in a targeted way. For example, if the police have reasonable grounds to suspect that particular individuals were going to engage in violence at a football game, they could be placed on a watchlist and LFR used to detect their presence in the vicinity.
“Or LFR can be deployed in a mass and untargeted way, selecting areas where a very large number of people are likely to pass and using a very large watchlist, in the hope that someone on the list will happen to pass by.
“It was precisely such mass and untargeted use that concerned the CA [Court of Appeal] in Bridges [the case against SWP], which discretion it considered had to be constrained.”
Unlike the case against SWP’s LFR use, however, which sought to determine the proportionality of the interferences with a specific person’s individual rights on the two occasions his biometric information was captured by the system, the judicial review seeks to challenge the lawfulness of the technology’s mass use.
“For the purpose of the IAWL [in accordance with law] requirement it is critical if there is mass use of LFR to repeatedly process the biometric data of millions of people with the capacity to transform public spaces,” it said. “When considering what is required in terms of constraints and safeguards to ensure a measure is IAWL, the Court must consider, among other things, the number of people a measure affects, and not a single individual’s rights.”
The Met, on the other hand, will argue that the public are “generally at liberty to avoid the relevant LFR area”, and that as individuals’ “familiarity” with LFR increases, it can be considered less rights-intrusive.
The force will also argue that, because officers’ discretion around LFR deployments is not unconstrained, the case is not an IAWL issue, asserting that “so long as the Court is satisfied there is not unfettered discretion on the constable deciding where to locate LFR, [there] is not a maintainable legality challenge.”
The Met added that because “there are no parts of the Policy that allow unfettered discretion for an officer to add whomever he or she wants to a watchlist or place the LFR camera wherever he or she wishes … there is no maintainable attack on the Policy as lacking the quality of law”.
In essence, the Met claims that questions about the breadth of officers’ discretion relate only to the proportionality of its approach, rather than its overall lawfulness.
Lack of primary legislation
The landmark legal challenge against LFR is being heard just a matter of weeks after the UK government pledged to “ramp up” the police use of facial recognition and biometrics.
While the use of LFR by police – beginning with the Met’s deployment at Notting Hill Carnival in August 2016 – has already ramped up massively in recent years, there has so far been minimal public debate or consultation, with the Home Office claiming for years that there is already “comprehensive” legal framework in place.
However, in December 2025, the Home Office launched a 10-week consultation on the use of LFR by UK police, allowing interested parties and members of the public to share their views on how the controversial technology should be regulated.
The department has said that although a “patchwork” legal framework for police facial recognition exists (including for the increasing use of the retrospective and “operator-initiated” versions of the technology), it does not give police themselves the confidence to “use it at significantly greater scale … nor does it consistently give the public the confidence that it will be used responsibly”.
It added that the current rules governing police LFR use are “complicated and difficult to understand”, and that an ordinary member of the public would be required to read four pieces of legislation, police national guidance documents and a range of detailed legal or data protection documents from individual forces to fully understand the basis for LFR use on their high streets.
There have also been repeated calls from both Parliament and civil society over many years for the police’s use of facial recognition to be regulated.
This includes three separate inquiries by the Justice and Home Affairs Committee into shoplifting, police algorithms and police facial recognition; two of the UK’s former biometrics commissioners, Paul Wiles and Fraser Sampson; an independent legal review by Matthew Ryder QC; the UK’s Equalities and Human Rights Commission; and the House of Commons Science and Technology Committee, which called for a moratorium on live facial recognition as far back as July 2019.
More recently, the Ada Lovelace Institute published a report in May 2025 that said the UK’s patchwork approach to regulating biometric surveillance technologies is “inadequate”, placing fundamental rights at risk and ultimately undermining public trust.
In August 2025, after being granted permission to intervene in the judicial review of the Met’s LFR use, the UK’s equality watchdog said the force is using the technology unlawfully, citing the need for its deployments to be necessary, proportionate and respectful of human rights.
