The technology is used through the police national database (PND) for retrospective facial recognition, where an image of a suspect is compared against more than 19 million custody photographs.
Police forces in the UK successfully lobbied to continue using a facial recognition system known to be biased against women, young people and ethnic minority groups, after complaining that a safer version generated fewer possible suspects.
Last week, the Home Office acknowledged that the system was biased following a review by the National Physical Laboratory (NPL), which found it misidentified Black and Asian people and women at much higher rates than white men. The government said it had acted on the findings. However, documents seen by the Guardian and Liberty Investigates show that this bias had been known for over a year, and that police forces actively sought to overturn measures designed to reduce it.
The NPCC Ordered The Reliability Threshold For Matches To Be Raised
Senior police leaders were informed in September 2024 that the system was more likely to generate incorrect matches for images of women, Black people and those aged 40 and under. In response, the National Police Chiefs’ Council (NPCC) ordered that the confidence threshold for matches be raised to reduce bias. This change sharply reduced the number of searches returning potential matches from 56% to 14%.
However, the decision was reversed just one month later after forces argued it had reduced the usefulness of the tool by generating fewer “investigative leads”. Although the current threshold has not been disclosed, the latest NPL analysis found that at some settings the system could falsely match Black women almost 100 times more often than white women. The Home Office described this as occurring only in “limited circumstances.”
Experts And Regulatory Bodies Expressed Serious Concerns!
Government consultation on expanding the use of facial recognition technology is now under way. Policing minister Sarah Jones has described the technology as the most significant breakthrough since DNA matching. However, experts and oversight bodies have raised serious concerns.
Prof Pete Fussey warned that prioritising convenience over fundamental rights could not withstand legal scrutiny. Abimbola Johnson, chair of the police race action plan oversight board, said the rollout of facial recognition had not been properly scrutinised despite clear risks of reinforcing racial disparities.
Chief Constable Amanda Blakeman, the NPCC lead for the PND, said safeguards and updated training were in place to limit the impact of bias and insisted the technology was being used responsibly. The Home Office added that a newly tested algorithm showed no statistically significant bias and would undergo further evaluation in early 2026. It stressed that human oversight remains central to every stage of the process and that public protection remains the priority.