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Law enforcement agencies across the UK effectively campaigned to use a facial recognition system acknowledged as discriminatory against women, young people, and individuals from ethnic minority groups, following complaints that a less biased version produced a reduced number of potential suspects.

The Technology in Practice

British police utilize the police national database (PND) to conduct retrospective facial recognition searches. This procedure entails matching a “probe image” of a suspect against a repository of over 19 million custody photos to find possible hits.

Admitted Bias

The UK interior ministry admitted last week that the technology was flawed. This acknowledgment followed a review by the National Physical Laboratory (NPL) found it incorrectly matched people of Black and Asian heritage and females at much greater frequency than white men. The ministry said it “had acted on the findings”.

“It prompts the issue of whether this technology only becomes effective if users tolerate biases in ethnicity and sex. Convenience is a poor argument for overriding fundamental rights.”

Known Issue

Official papers show that this discriminatory flaw has been recognized for over twelve months. Furthermore, law enforcement argued to overturn an earlier ruling that was intended to address the problem.

Police bosses were notified of the algorithmic discrimination in September 2024. The Home Office-commissioned laboratory study concluded the system was had a higher probability to produce false positives for photos of women, Black people, and those aged 40 and under.

A Reversed Decision

In reaction, the National Police Chiefs’ Council (NPCC) mandated that the confidence threshold required for possible hits be increased to a level where the bias was greatly diminished.

However, this decision was reversed the next month after forces complained that the adjusted system was generating a lower number of “investigative leads”. Internal records indicate the stricter setting cut the number of searches that yielded possible identifications from over half to a just 14%.

Profound Inequalities

Although the Home Office and NPCC refused to say what setting is currently used, the recent NPL study found the system could generate incorrect matches for Black women nearly a hundred times more frequently than for Caucasian women at specific configurations.

The Home Office commented on these results: “Our evaluation found that in a specific scenarios the software is more likely to wrongly flag some demographic groups in its search results.”

Operational Effectiveness vs. Bias

Describing the impact of the brief increase to the system's confidence threshold, the police records state: “This adjustment significantly reduces the effect of discrimination across legally safeguarded attributes of race, age and sex but had a significant negative impact on police efficiency”. The documents add that police units complained that “a previously useful tool now delivered outcomes of limited benefit”.

Wider Implementation Proposals

Meanwhile, the UK administration has opened a ten-week public review on its proposals to widen the use of facial recognition technology. Policing minister Sarah Jones has labeled the technology as the “most significant advance since DNA matching”.

Criticism from Advisors and Monitors

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

“This disclosure show yet again that the anti-racism commitments the police has made via the race action plan are failing to be integrated into broader operations. Our reports have cautioned that innovative tools are being rolled out in a landscape where ethnic inequalities, weak scrutiny and poor data collection continue to exist.

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

Home Office Response

A Home Office spokesperson stated: “The Home Office takes the conclusions of the study with utmost gravity and we have implemented changes. A updated software has been independently tested and acquired, which has demonstrated no measurable discrimination. It will be trialled early next year and will be subject to evaluation.

“The foremost aim is protecting the public. This gamechanging technology will assist officers to apprehend and prosecute offenders. There is human involvement in each stage of the process and no further action would be pursued without trained officers meticulously examining the output.”