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Law enforcement agencies across the United Kingdom effectively campaigned to deploy a facial recognition system known to be discriminatory against women, youths, and members of ethnic minority groups, following complaints that a less biased version generated fewer investigative leads.

The Technology in Practice

British police utilize the police national database (PND) to carry out searches using historical face recognition. This process entails comparing a reference photograph of a suspect against a repository of over 19 million mugshots to identify possible hits.

Admitted Bias

The Home Office admitted last week that the technology was biased. This acknowledgment came after a study by the National Physical Laboratory (NPL) determined it misidentified Black and Asian people and women at significantly higher rates than Caucasian males. The ministry stated it “took steps on the findings”.

“This raises the question of whether this technology only becomes useful if users tolerate biases in race and sex. Convenience is a weak argument for overriding fundamental rights.”

Known Issue

Internal documents reveal that this discriminatory flaw has been known about for more than a year. Furthermore, law enforcement lobbied to reverse an initial decision that was intended to mitigate the problem.

Police bosses were informed of the algorithmic discrimination in September 2024. The government-ordered NPL review concluded the system was had a higher probability to suggest incorrect matches for images depicting women, individuals of Black ethnicity, and those aged 40 and under.

A Policy U-Turn

In reaction, the national police leadership body ordered that the confidence threshold required for potential matches be raised to a point where the bias was significantly reduced.

However, this decision was reversed the following month after forces complained that the modified technology was generating a lower number of “investigative leads”. Internal records indicate the stricter setting cut the proportion of queries that yielded potential matches from over half to a just 14%.

Profound Inequalities

Although the Home Office and NPCC declined to specify what setting is now in operation, the recent independent review discovered the system could produce incorrect matches for Black women almost 100 times more often than for white women at specific configurations.

The Home Office commented on these findings: “Our evaluation identified that in a limited set of circumstances the software is more likely to wrongly flag some population segments in its match reports.”

Operational Effectiveness vs. Bias

Describing the impact of the temporary raise to the system's accuracy setting, the police records state: “This adjustment significantly reduces the impact of discrimination across protected characteristics of race, age and gender but had a substantially detrimental effect on operational effectiveness”. The documents further note that forces argued that “a previously useful tool now delivered outcomes of questionable value”.

Broader Rollout Plans

Meanwhile, the UK administration has opened a two-and-a-half-month public review on its proposals to expand the use of facial recognition technology. The minister for police Sarah Jones has labeled the tool as the “biggest breakthrough since DNA matching”.

Expert and Oversight Concerns

Abimbola Johnson, chair of the advisory panel for the police race action plan, said: “There was scant consideration through race action plan meetings of the technology deployment despite clear relevance with the strategy's goals.

“These revelations show once again that the anti-racism commitments policing has undertaken via the equality initiative are not being translated into wider practice. Independent assessments have warned that innovative tools are being implemented in a landscape where racial disparities, inadequate oversight and faulty information gathering already persist.

“Any use of this technology must adhere to strict national standards, be subject to external review, and demonstrate it diminishes rather than compounds racial disparity.”

Official Statement

A Home Office spokesperson said: “We treat the conclusions of the report with utmost gravity and we have already taken action. A new algorithm has been externally evaluated and procured, which has no statistically significant bias. It will be tested early next year and will be undergo evaluation.

“Our priority is protecting the public. This gamechanging technology will assist officers to apprehend and prosecute offenders. There is officer review in each stage of the process and no further action would be pursued without specialist personnel carefully reviewing the results.”