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Law enforcement agencies across the United Kingdom successfully lobbied to deploy a facial recognition system acknowledged as discriminatory against women, youths, and members of ethnic minority groups, following complaints that a more accurate version produced fewer investigative leads.

The Technology in Practice

British police utilize the national police database to conduct searches using historical face recognition. This process involves comparing a reference photograph of a person of interest against a repository of over 19 million mugshots to find potential matches.

Acknowledged Discrimination

The Home Office admitted last week that the system was biased. This acknowledgment came after a review by the National Physical Laboratory (NPL) determined it incorrectly matched Black and Asian people and women at much greater frequency than white men. The Home Office stated it “had acted on the findings”.

“It prompts the issue of whether facial recognition only becomes effective if users accept discrimination in ethnicity and gender. Operational ease is a poor argument for disregarding fundamental rights.”

Long-Standing Problem

Internal documents show that this bias has been known about for more than a year. Furthermore, police forces argued to overturn an earlier ruling that was intended to mitigate the problem.

Police bosses were notified of the algorithmic discrimination in September 2024. The government-ordered NPL review concluded the system was more likely to suggest incorrect matches for images depicting women, Black people, and those under 40 years old.

A Policy U-Turn

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

However, this decision was reversed the following month after forces complained that the adjusted system was producing a lower number of “investigative leads”. Internal records show the stricter setting cut the proportion of searches resulting in possible identifications from 56% to a mere 14%.

Profound Inequalities

Although the authorities refused to say what setting is currently used, the recent independent review discovered the system could produce false positives for women of Black heritage almost 100 times more frequently than for Caucasian women at specific configurations.

The ministry stated on these findings: “Our evaluation found that in a limited set of circumstances the software is has a greater tendency to wrongly flag some population segments in its match reports.”

Balancing Utility and Fairness

Describing the impact of the brief increase to the system's confidence threshold, the police records state: “This adjustment greatly lessens the effect of bias across protected characteristics of ethnicity, age and sex but had a significant negative impact on police efficiency”. The papers add that police units argued that “a once effective tactic now delivered results of limited benefit”.

Broader Rollout Plans

Meanwhile, the UK administration has opened a ten-week consultation on its plans to widen the use of biometric scanning systems. The minister for police Sarah Jones has described the tool as the “most significant advance since genetic fingerprinting”.

Criticism from Advisors and Monitors

Abimbola Johnson, head of the advisory panel for the national policing equality strategy, commented: “We observed very little discussion through race action plan meetings of the technology deployment despite clear relevance with the plan’s concerns.

“These revelations demonstrate yet again that the anti-racism commitments the police has made via the race action plan are failing to be integrated into broader operations. 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 this technology must adhere to rigorous official guidelines, be independently scrutinised, and prove it diminishes rather than exacerbates racial disparity.”

Home Office Response

A government representative stated: “We treat the conclusions of the study seriously and we have implemented changes. A updated software has been independently tested and acquired, which has no statistically significant bias. It will be trialled early next year and will be undergo evaluation.

“The foremost aim is protecting the public. This gamechanging technology will assist officers to apprehend and prosecute offenders. There is officer review in each stage of the procedure and no arrest or charge would be pursued without specialist personnel carefully reviewing the output.”