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Law enforcement agencies across the UK successfully lobbied to use a facial recognition system known to be discriminatory against women, young people, and members of ethnic minority groups, following complaints that a less biased version produced fewer investigative leads.

How the System Works

British police utilize the police national database (PND) to carry out retrospective facial recognition searches. This procedure involves comparing a reference photograph of a suspect against a database of over 19 million mugshots to identify possible hits.

Acknowledged Discrimination

The Home Office conceded last week that the system was flawed. This acknowledgment came after a review by the government's National Physical Laboratory determined it misidentified Black and Asian people and females at much greater frequency than Caucasian males. The ministry said it “took steps on the findings”.

“This raises the question of whether facial recognition only becomes useful if users tolerate biases in ethnicity and sex. Operational ease is a weak argument for disregarding fundamental rights.”

Long-Standing Problem

Internal documents reveal that this discriminatory flaw has been known about for over twelve months. Furthermore, police forces argued to overturn an initial decision that was intended to address the problem.

Police bosses were informed of the system's bias in late 2024. The government-ordered laboratory study concluded the system was more likely to produce false positives for photos of females, individuals of Black ethnicity, and those under 40 years old.

A Reversed Decision

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

However, this directive was overturned the next month after forces complained that the adjusted system was producing fewer “investigative leads”. Internal records indicate the stricter setting reduced the number of queries resulting in potential matches from 56% to a just under 15%.

Profound Inequalities

Although the Home Office and NPCC declined to specify what setting is now in operation, the recent NPL study discovered the system could generate false positives for Black women nearly a hundred times more often than for Caucasian women at certain settings.

The Home Office commented on these results: “Our evaluation found that in a specific scenarios the algorithm is has a greater tendency to wrongly flag some population segments in its match reports.”

Operational Effectiveness vs. Bias

Outlining the impact of the brief increase to the system's confidence threshold, the NPCC documents state: “The change greatly lessens the impact of discrimination across legally safeguarded attributes of race, age and sex but had a significant negative impact on police efficiency”. The papers further note that police units argued that “a once effective tactic returned outcomes of limited benefit”.

Broader Rollout Plans

Meanwhile, the government has opened a two-and-a-half-month consultation on its proposals to widen the use of facial recognition technology. Policing minister Sarah Jones has described the technology as the “most significant advance since genetic fingerprinting”.

Expert and Oversight Concerns

Abimbola Johnson, head of the independent scrutiny and oversight board for the national policing equality strategy, said: “There was scant consideration in race action plan meetings of the facial recognition rollout despite clear relevance with the plan’s concerns.

“This disclosure demonstrate once again that the anti-racism commitments policing has undertaken via the race action plan are failing to be integrated into wider practice. Independent assessments have warned that new technologies are being implemented in a context where racial disparities, weak scrutiny and faulty information gathering already persist.

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

Home Office Response

A government representative said: “The Home Office treat the conclusions of the report with utmost gravity and we have implemented changes. A new algorithm has been independently tested and acquired, which has no statistically significant bias. It will be tested early next year and will be undergo further assessment.

“The foremost aim is protecting the public. This revolutionary tool will support officers to apprehend and prosecute offenders. There is officer review in every step of the procedure and no arrest or charge would be pursued without specialist personnel meticulously examining the output.”