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Police forces across the United Kingdom successfully lobbied to deploy a facial recognition system acknowledged as discriminatory against females, young people, and individuals from ethnic minority groups, after complaining that a more accurate version produced fewer potential suspects.

The Technology in Practice

British police use the national police database to carry out retrospective facial recognition searches. This procedure entails matching a reference photograph of a person of interest against a database of over 19 million mugshots to identify potential matches.

Acknowledged Discrimination

The UK interior ministry conceded last week that the technology was flawed. This admission followed a review by the National Physical Laboratory (NPL) determined it misidentified Black and Asian people and women at much greater frequency than Caucasian males. The Home Office said it “took steps on the findings”.

“It prompts the issue of whether facial recognition only becomes effective if users accept biases in race and gender. Convenience is a weak argument for disregarding fundamental rights.”

Long-Standing Problem

Internal documents show that this bias has been known about for more than a year. Furthermore, law enforcement lobbied to reverse an earlier ruling that was intended to address the problem.

Senior officers were informed of the system's bias in September 2024. The Home Office-commissioned NPL review concluded the system was had a higher probability to produce incorrect matches for photos of women, Black people, and those aged 40 and under.

A Reversed Decision

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

However, this decision was overturned the next month after forces complained that the modified technology was producing a lower number of “investigative leads”. NPCC documents show the stricter setting reduced the proportion of queries that yielded potential matches from over half to a just 14%.

Profound Inequalities

Although the authorities refused to say what threshold is now in operation, the latest independent review found the system could produce false positives for Black women nearly a hundred times more frequently than for white women at specific configurations.

The Home Office stated on these results: “The testing identified that in a limited set of circumstances the algorithm is more likely to incorrectly include 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 NPCC documents state: “This adjustment significantly reduces the impact of discrimination across protected characteristics of race, generation and gender but had a substantially detrimental effect on police efficiency”. The documents further note that police units argued that “a previously useful tool returned outcomes of limited benefit”.

Broader Rollout Plans

Meanwhile, the UK administration has launched a two-and-a-half-month consultation on its plans to expand the use of facial recognition technology. The minister for police Sarah Jones has described the technology as the “most significant advance since genetic fingerprinting”.

Expert and Oversight Concerns

The chair of a police oversight board, chair of the independent scrutiny and oversight board for the police race action plan, said: “There was very little consideration through race action plan meetings of the technology deployment despite clear relevance with the strategy's goals.

“These revelations demonstrate once again that the pledges to combat discrimination policing has made through the equality initiative are failing to be integrated into broader operations. Our reports have cautioned that innovative tools are being rolled out in a landscape where racial disparities, weak scrutiny and faulty information gathering continue to exist.

“Any use of this technology must adhere to rigorous official guidelines, be independently scrutinised, and prove it reduces rather than exacerbates ethnic bias.”

Home Office Response

A Home Office spokesperson stated: “The Home Office takes the findings of the report with utmost gravity and we have already taken action. A updated software has been externally evaluated and acquired, which has demonstrated no measurable discrimination. It will be trialled in the coming months and will be subject to evaluation.

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