Peter Doyle KC
(Judicial review – police use of facial recognition technology in London – Shaun Thompson and another v The Metropolitan Police Commissioner (2026) EWHC 915 (Admin))
The Recognition Software
The Metropolitan Police Service (“MPS”) adopted live facial recognition technology (“LFR”) in September 2024. Under its policy, the technology is used across London to prevent and detect crime, locate missing persons and protect the public. Individuals of interest to the police are placed on LFR watchlists.
Police generally deploy movable rather than fixed cameras. The software compares captured facial images with images already known to the police. It converts those images into unique biometric values and searches for a match. Where no match is found, the system automatically and immediately deletes the captured data.
Contention
The claimants argued that the policy breached Article 8 of the European Convention on Human Rights because it interfered with the right to respect for private and family life (Ground 1).
They also claimed that the policy breached Articles 10 and 11. In their view, the policy was neither prescribed by law nor in accordance with the law. They argued that it interfered with freedom of expression and the right to freedom of assembly and association (Ground 2).
The first claimant was wrongly identified by the system as his brother, who appeared on a watchlist. Although officers questioned whether he was the same person, they stopped and questioned him. Officers also requested his fingerprints. When he refused, they threatened him with arrest.
The second claimant was a director of Big Brother Watch. In both her professional and personal capacities, she monitored the use of LFR in London and protested against its increasing deployment.
The Central Issue
According to the court, the key issue was whether the policy was lawful and whether its existence, meaning and consequences were foreseeable to those affected by it.
For a measure to comply with Article 8(2), it must have a basis in domestic law. The law must also be sufficiently clear, accessible and foreseeable so that individuals can understand the consequences of its application. In addition, it must be compatible with the rule of law.
As Lord Sumption explained in In Re Gallagher (2019) UKSC 3:
“The measure must not confer a discretion so broad that its scope is in practice dependent on the will of those who apply it, rather than on the law itself.”
Sufficient clarity and foreseeability are therefore required to prevent arbitrary decision-making. Public authorities must not act on whim, caprice, malice or personal preference.
Neither the claimants nor the court were concerned with the merits of the policy itself. The challenge focused solely on whether it satisfied the legal requirements.
The ECHR
The court addressed the law as it applies to the relevant Articles (see paragraphs 34-39).
Police Duties
The police owe to the public a common law duty to prevent and detect crime. That function can include the use, retention and disclosure of images of individuals. In Bridges the Divisional Court (upheld by the Court of Appeal see (2020) 1 WLR 5037)held that the police may make reasonable use of a person’s photograph for policing purposes. Hence the use of CCTV, ANPR and body worn video footage. However, specific statutory authority is required for “intrusive measures” for example to take fingerprints, to enter a property to search and to take a DNA sample.
Agreed Fact -v- Issue in the Case
The compilation of a watchlist falls within the statutory powers of the police in relation to arrested persons and by common law in relation to other persons of “possible interest” being steps necessary for keeping the peace, preventing crime or protecting property.
None of this was in issue; the issue was whether the MPS Policy met the necessary tests.
The Tests
This called for a reminder of what Lord Bingham pithily explained in Gillan v United Kingdom (2010) 50 EHRR:
“The lawfulness requirement in the Convention addresses supremely important features of the rule of law. The exercise of power by public officials, as it affects members of the public, must be governed by clear and publicly accessible rules of law. The public must not be vulnerable to interference by public officials acting on any personal whim, caprice, malice, predilection or purpose other than that for which the power was conferred. That is what, in this context, is meant by arbitrariness, which is the antithesis of legality.”
This is the requirement that the measure be both compatible with the rule of law and foreseeable in terms of its existence, meaning and consequences.
The key question is whether the exercise of the power is subject to principles, whether set out in law, policy or a combination of the two, which suffice to prevent decisions being dependent on the will of the decision-maker or arbitrary.
The LFR constraints and safeguards
Despite the broad purpose of the Policy the court recognised significant constraints because LFR technology may only be used in three specific sets of circumstances. For the analysis of the prescribed circumstances see 94-116 of the judgment.
In short it can be used (i) to police either a crime or missing person “hotspot”, (ii) to protect “protective security operations” and (iii) to locate people based on specific intelligence.
The Policy had a number of built-in safeguards.
It is mandatory for those who authorise LFR deployment to consider whether any particular deployment would be “a proportionate means of achieving the MPS’ policing objectives (see para 6.1 of the Policy which itself draws attention to the relevant Convention rights).
The Policy sets out stress tests for considering in three separate stages whether deployment of LFR would be proportionate in the particular circumstances.
It identifies the specific roles and duties of the officers who carry out LFR deployment. It includes rolls to be performed by Gold, Silver and Bronze Commanders.
It also contains significant safeguards against the arbitrary deployment of LFR including the provision on application for its use of (i) a Community Impact Assessment (ii) an Equality Assessment and (iii) a Data Protection Impact Assessment. Other documents also complemented the Policy.
Conclusions
The court reached six principal conclusions:-
- The more intrusive the act complained of the more precise and specific must be the law said to justify it
- The Policy contained sufficient safeguards against arbitrary use
- The advance of technology, in particular Artificial Intelligence, did not engage the terms of the Policy under challenge nor its current lawfulness
- There was no evidence that the Policy failed on the grounds of discrimination
- It did not require the police to spell out in its published material every instance and every circumstance in which it will exercise a discretion or power
- The Policy was proportionate and provided the claimants with an adequate indication of the circumstances in which LFR will be used and will enable them to foresee, to a degree that is reasonable in the circumstances, the consequences of travelling in an area of London where LFR is in use.
Accordingly, the Policy was prescribed, was in accordance with the law, and its existence, meaning and consequences were both accessible and foreseeable.
Both grounds for challenge failed.
NB. 1. The court only addressed current technology and did not second-guess how matters might be considered if more advanced technology was deployed at some future date. Clearly an issue could arise as to whether any more sophisticated means of intrusion were in all the circumstances disproportionate to the policing objectives.
2. The court considered witness statements filed on behalf of the claim and having done so emphasised that evidence given in support of a claim for judicial review must be relevant to determine the question of public law raised in the pleaded case. A duty to the court was imposed on a party’s lawyer to consider with care and objectivity whether the evidence put before the court – from a client or otherwise – is relevant and, if not, then to advise that it is inadmissible and a client should heed such advice. If this is not done, then costs implications may follow.