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Law enforcement agencies across the UK effectively campaigned to use a facial recognition system known to be biased against females, young people, and members of ethnic minority groups, after complaining that a less biased version generated a reduced number of potential suspects.

The Technology in Practice

UK forces utilize the national police database to conduct retrospective facial recognition searches. This process entails comparing a reference photograph of a person of interest against a database of more than 19 million custody photos to identify potential matches.

Acknowledged Discrimination

The UK interior ministry admitted last week that the system was biased. This acknowledgment came after a review by the National Physical Laboratory (NPL) determined it misidentified people of Black and Asian heritage and females at much greater frequency than white men. The Home Office said it “had acted on the findings”.

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

Long-Standing Problem

Official papers show that this discriminatory flaw has been recognized for over twelve months. Furthermore, law enforcement lobbied to reverse an earlier ruling that was intended to mitigate the problem.

Police bosses were informed of the algorithmic discrimination in late 2024. The government-ordered NPL review found the system was more likely to suggest incorrect matches for photos of females, individuals of Black ethnicity, and those aged 40 and under.

A Policy U-Turn

In response, the national police leadership body ordered that the accuracy setting required for potential matches be raised to a level where the disparity was significantly reduced.

However, this decision was reversed the next month following complaints from police that the adjusted system was producing fewer “useful lines of inquiry”. Internal records show the stricter setting cut the proportion of queries resulting in potential matches from 56% to a just 14%.

Severe Disparities

Although the authorities refused to say what setting is now in operation, the recent NPL study discovered the system could produce incorrect matches for Black women almost 100 times more frequently than for white women at specific configurations.

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

Balancing Utility and Fairness

Describing the impact of the brief increase to the system's accuracy setting, the NPCC documents state: “This adjustment greatly lessens the impact of bias across legally safeguarded attributes of ethnicity, generation and gender but had a substantially detrimental effect on police efficiency”. The papers add that forces complained 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 widen the use of biometric scanning systems. The minister for police Sarah Jones has described the technology as the “biggest breakthrough since genetic fingerprinting”.

Criticism from Advisors and Monitors

The chair of a police oversight board, chair of the independent scrutiny and oversight board for the national policing equality strategy, commented: “We observed scant discussion through race action plan meetings of the technology deployment even with clear relevance with the strategy's goals.

“This disclosure show once again that the pledges to combat discrimination policing has undertaken through the race action plan are not being translated into broader operations. Our reports have cautioned that innovative tools are being implemented in a context where racial disparities, weak scrutiny and faulty information gathering continue to exist.

“All deployment of this technology must adhere to strict national standards, be subject to external review, and demonstrate it reduces rather than exacerbates racial disparity.”

Official Statement

A Home Office spokesperson stated: “The Home Office takes the conclusions of the study seriously and we have already taken action. A updated software has been independently tested and procured, which has no statistically significant bias. It will be tested early next year and will be subject to evaluation.

“The foremost aim is protecting the public. This revolutionary tool will support police to apprehend and prosecute offenders. There is human involvement in each stage of the procedure and no arrest or charge would be pursued without specialist personnel carefully reviewing the results.”