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Police forces across the UK effectively campaigned to use a facial recognition system known to be discriminatory against females, young people, and members of ethnic minority groups, following complaints that a more accurate version produced a reduced number of investigative leads.

How the System Works

UK forces use the police national database (PND) to carry out searches using historical face recognition. This procedure entails comparing a “probe image” of a person of interest against a repository of more than 19 million custody photos to identify possible hits.

Acknowledged Discrimination

The Home Office conceded last week that the system was biased. This acknowledgment followed a study by the National Physical Laboratory (NPL) determined it misidentified people of Black and Asian heritage and females at significantly higher rates than white men. The Home Office said it “took steps on the findings”.

“This raises the question of whether facial recognition only becomes effective if users tolerate discrimination in ethnicity and gender. Operational ease is a weak argument for disregarding basic freedoms.”

Long-Standing Problem

Official papers show that this bias has been known about for over twelve months. Furthermore, police forces argued to overturn an initial decision that was intended to mitigate the problem.

Police bosses were notified of the system's bias in late 2024. The government-ordered NPL review concluded the system was more likely to produce incorrect matches for photos of women, Black people, and those under 40 years old.

A Policy U-Turn

In reaction, the National Police Chiefs’ Council (NPCC) ordered that the accuracy setting required for potential matches be raised to a level where the disparity was significantly reduced.

However, this decision was overturned the following month following complaints from police that the modified technology was generating fewer “investigative leads”. NPCC documents indicate the stricter setting cut the proportion of queries that yielded possible identifications from over half to a just under 15%.

Profound Inequalities

Although the authorities refused to say what setting is now in operation, the latest independent review found the system could generate false positives for Black women almost 100 times more frequently than for white women at specific configurations.

The ministry stated on these findings: “Our evaluation identified that in a specific scenarios the software is more likely to wrongly flag some demographic groups in its search results.”

Balancing Utility and Fairness

Outlining the impact of the temporary raise to the system's accuracy setting, the police records note: “The change significantly reduces the impact of bias across protected characteristics of ethnicity, generation and sex but had a significant negative impact on operational effectiveness”. The papers add that forces argued that “a previously useful tool now delivered outcomes of questionable value”.

Wider Implementation Proposals

Meanwhile, the UK administration has launched a ten-week consultation on its plans to expand the use of biometric scanning systems. The minister for police Sarah Jones has labeled the tool as the “most significant advance since DNA matching”.

Criticism from Advisors and Monitors

Abimbola Johnson, head of the advisory panel for the police race action plan, commented: “There was very little discussion through race action plan meetings of the facial recognition rollout even with clear relevance with the plan’s concerns.

“These revelations show yet again that the anti-racism commitments policing has undertaken through the race action plan are failing to be integrated into broader operations. Independent assessments have warned that new technologies are being rolled out in a context where racial disparities, inadequate oversight and faulty information gathering already persist.

“Any use of facial recognition must adhere to rigorous official guidelines, be independently scrutinised, and prove it diminishes rather than compounds racial disparity.”

Official Statement

A government representative stated: “We takes the conclusions of the report seriously and we have implemented changes. A new algorithm has been independently tested and acquired, which has no statistically significant bias. It will be trialled in the coming months and will be undergo evaluation.

“Our priority is ensuring public safety. This revolutionary tool will assist officers to put criminals and rapists behind bars. There is officer review in every step of the process and no further action would be pursued without specialist personnel meticulously examining the output.”