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Law enforcement agencies across the UK successfully lobbied to deploy a facial recognition system known to be biased against females, youths, and members of minority ethnic backgrounds, after complaining that a more accurate version produced fewer investigative leads.

How the System Works

UK forces utilize the national police database to conduct retrospective facial recognition searches. This procedure entails matching a reference photograph of a suspect against a database of over 19 million mugshots to find possible hits.

Admitted Bias

The Home Office admitted last week that the technology was biased. This admission came after a study by the government's National Physical Laboratory found it incorrectly matched people of Black and Asian heritage and women at much greater frequency than Caucasian males. The ministry said it “had acted on the findings”.

“It prompts the question of whether this technology only becomes useful if users tolerate discrimination in ethnicity and sex. Operational ease is a poor argument for overriding basic freedoms.”

Known Issue

Official papers show that this bias has been recognized for over twelve months. Furthermore, police forces argued to overturn an initial decision that was designed to address the problem.

Police bosses were notified of the algorithmic discrimination in late 2024. The government-ordered NPL review concluded the system was had a higher probability to produce incorrect matches for photos of females, Black people, and those aged 40 and under.

A Reversed Decision

In reaction, the national police leadership body mandated that the confidence threshold required for possible hits be increased to a point where the disparity was significantly reduced.

However, this decision was reversed the following month following complaints from police that the modified technology was producing a lower number of “investigative leads”. Internal records show the higher threshold reduced the number of queries resulting in possible identifications from 56% to a mere 14%.

Profound Inequalities

Although the authorities refused to say what threshold is now in operation, the latest independent review discovered the system could produce false positives for women of Black heritage almost 100 times more often than for white women at specific configurations.

The ministry stated on these findings: “Our evaluation found that in a specific scenarios the software is has a greater tendency to wrongly flag some demographic groups in its match reports.”

Balancing Utility and Fairness

Describing the impact of the brief increase to the system's accuracy setting, the NPCC documents note: “The change greatly lessens the effect of bias across legally safeguarded attributes of ethnicity, generation and gender but had a significant negative impact on operational effectiveness”. The documents add that forces argued that “a previously useful tool now delivered results of limited benefit”.

Broader Rollout Plans

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

Expert and Oversight Concerns

Abimbola Johnson, head of the advisory panel for the police race action plan, commented: “There was very little consideration through race action plan meetings of the facial recognition rollout despite clear relevance with the strategy's goals.

“This disclosure demonstrate once again that the anti-racism commitments the police has made through the equality initiative are failing to be integrated into wider practice. Our reports have cautioned that innovative tools are being rolled out in a landscape where ethnic inequalities, inadequate oversight and poor data collection already persist.

“Any use of facial recognition must meet strict national standards, be independently scrutinised, and prove it diminishes rather than exacerbates ethnic bias.”

Home Office Response

A Home Office spokesperson said: “We treat the conclusions of the study seriously and we have already taken action. A new algorithm 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.

“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 trained officers carefully reviewing the output.”