Facial Recognition Errors Put Innocent People and Ethnic Minorities at Risk of Wrongful Arrest, UK Police Watchdog Warns
Police officers in Britain risk arresting innocent people, especially from ethnic minorities, if they treat inaccurate facial recognition data as evidence, an official report published on Wednesday has found. The report by His Majesty's Inspectorate of Constabulary (HMICFRS) covers only retrospective facial recognition, in which past images are searched for matches.
Although the technology can help fight crime, the report found it is beset by errors and biases, and operators do not always realise they must make further inquiries to verify the data. Some investigators did not know that retrospective facial recognition results were intelligence rather than evidence and required further enquiries before officers took enforcement action.
Inspectors found that some investigators did not always carry out enough corroborative enquiries before acting on potential matches. In a small number of cases, officers relied too heavily on the results, which led to inappropriate investigative action. This creates a risk that people could be incorrectly identified or arrested, which could undermine public confidence in the technology.
The report said there are still issues with bias in the algorithm, including being more likely to wrongly flag people from ethnic minorities as suspects. Auditors also identified cases where users uploaded poor-quality or unsuitable probe images, including blurred images and images containing multiple faces, which reduced the system's ability to return reliable matches.
Inspectors also found a risk of public confidence being undermined because custody images that should have been deleted were in fact kept.
The report says legislation has not kept up with changes in facial recognition technology and there is no comprehensive statutory framework governing its use. This makes it more difficult for forces to understand the lawful basis for using retrospective facial recognition and what safeguards are needed to protect the public.
His Majesty's Inspector of Constabulary Kathryn Stone said continued public support relied on showing the technology was being used properly. Police forces, she said, must be able to show that appropriate safeguards are in place, risks relating to bias and data retention are effectively managed, and decisions are still subject to human judgment. A clearer statutory framework, stronger national standards and improved governance and oversight arrangements are essential to maintaining public confidence.
Facial recognition is seen by police chiefs as the next big leap forward in crime fighting, and by sceptics as the next huge threat to civil liberties. Jasleen Chaggar, from Big Brother Watch, said the revelation that officers are treating facial recognition as bona fide evidence rather than a probability score is alarming.
In Chaggar's words, this approach significantly increases the risk that more innocent people will have officers knock on their door to arrest them for crimes committed in towns they have never visited, as has been seen before. Worse still, police are not even logging their use of retrospective facial recognition, meaning people could wrongfully become suspects in criminal investigations without even realising why they have been accused.
Ben Russell, lead on facial recognition for the National Police Chiefs' Council, said policing remains committed to the ethical, proportionate and responsible use of retrospective facial recognition to help investigate crime, bring offenders to justice and keep communities safe, and that the council was pleased the inspectorate had recognised the technology's possibilities.
Prof Pete Fussey of the University of Southampton, formerly a police adviser on facial recognition, said meaningful human scrutiny of AI systems is a legal requirement, yet the report gives examples of investigators taking the computer's suggestions at face value without further checks.
