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Police forces across the United Kingdom successfully lobbied to use a facial recognition system acknowledged as discriminatory against females, young people, and individuals from minority ethnic backgrounds, after complaining that a more accurate version produced a reduced number of potential suspects.

How the System Works

UK forces utilize the police national database (PND) to conduct retrospective facial recognition searches. This process entails comparing a reference photograph of a suspect against a database of more than 19 million custody photos to find possible hits.

Acknowledged Discrimination

The Home Office conceded last week that the technology was flawed. This acknowledgment came after a study by the National Physical Laboratory (NPL) determined it misidentified Black and Asian people and women at much greater frequency than white men. The ministry stated it “had acted on the findings”.

“This raises the issue of whether this technology only becomes useful if users accept discrimination in race and sex. Operational ease is a poor argument for disregarding basic freedoms.”

Long-Standing Problem

Official papers show that this discriminatory flaw has been known about for over twelve months. Furthermore, police forces argued to overturn an earlier ruling that was designed to address the problem.

Senior officers were notified of the algorithmic discrimination in September 2024. The Home Office-commissioned laboratory study concluded the system was more likely to suggest false positives for photos of women, Black people, and those under 40 years old.

A Policy U-Turn

In response, the national police leadership body ordered that the accuracy setting required for potential matches be increased to a point where the disparity was greatly diminished.

However, this directive was reversed the next month following complaints from police that the adjusted system was generating a lower number of “investigative leads”. NPCC documents show the higher threshold cut the number of searches resulting in potential matches from over half to a mere 14%.

Severe Disparities

Although the Home Office and NPCC declined to specify what threshold is currently used, the latest NPL study discovered the system could produce incorrect matches for women of Black heritage nearly a hundred times more often than for white women at specific configurations.

The ministry stated on these findings: “The testing identified that in a limited set of circumstances the software is more likely to incorrectly include some demographic groups in its search results.”

Balancing Utility and Fairness

Describing the impact of the temporary raise to the system's accuracy setting, the NPCC documents note: “The change significantly reduces the effect of bias across legally safeguarded attributes of race, age and sex but had a significant negative impact on operational effectiveness”. The papers add that forces argued that “a previously useful tool now delivered results of questionable value”.

Wider Implementation Proposals

Meanwhile, the government has opened a ten-week consultation on its plans to widen the use of facial recognition technology. Policing minister Sarah Jones has labeled the tool as the “most significant advance since genetic fingerprinting”.

Criticism from Advisors and Monitors

Abimbola Johnson, head of the advisory panel for the police race action plan, commented: “There was scant consideration through equality strategy sessions of the facial recognition rollout even with obvious cross-over with the strategy's goals.

“These revelations show yet again that the anti-racism commitments the police has undertaken through the race action plan are not being translated into wider practice. Independent assessments have cautioned that new technologies are being implemented in a landscape where racial disparities, inadequate oversight and faulty information gathering already persist.

“Any use of facial recognition must meet rigorous official guidelines, be subject to external review, and prove it diminishes rather than exacerbates racial disparity.”

Official Statement

A Home Office spokesperson said: “We treat the conclusions of the study seriously and we have implemented changes. A updated software has been independently tested and procured, which has no statistically significant bias. It will be tested in the coming months and will be subject to evaluation.

“Our priority is protecting the public. This revolutionary tool will assist officers to apprehend and prosecute offenders. There is human involvement in every step of the procedure and no arrest or charge would be taken without specialist personnel meticulously examining the output.”