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Police forces across the United Kingdom successfully lobbied to deploy a facial recognition system known to be discriminatory against women, young people, and members of minority ethnic backgrounds, following complaints that a more accurate version produced a reduced number of investigative leads.

How the System Works

British police utilize the national police database to conduct retrospective facial recognition searches. This process entails matching a “probe image” of a person of interest against a repository of over 19 million mugshots to find possible hits.

Acknowledged Discrimination

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

“This raises the issue of whether this technology only becomes effective if users tolerate discrimination in ethnicity and gender. Convenience is a poor argument for disregarding fundamental rights.”

Long-Standing Problem

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

Senior officers were informed of the algorithmic discrimination in September 2024. The Home Office-commissioned laboratory study found the system was had a higher probability to suggest false positives for photos of women, individuals of Black ethnicity, and those under 40 years old.

A Policy U-Turn

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

However, this directive was reversed the following month after forces complained that the modified technology was generating fewer “investigative leads”. NPCC documents show the higher threshold cut the proportion of queries that yielded possible identifications from over half to a just under 15%.

Profound Inequalities

Although the authorities refused to say what setting is now in operation, the latest NPL study found the system could produce incorrect matches for Black women nearly a hundred times more frequently than for white women at specific configurations.

The Home Office commented on these results: “The testing identified that in a limited set of circumstances the software is more likely to incorrectly include some population segments in its match reports.”

Balancing Utility and Fairness

Outlining the effect of the brief increase to the system's accuracy setting, the police records note: “The change greatly lessens the impact of discrimination across legally safeguarded attributes of race, generation and gender but had a significant negative impact on police efficiency”. The documents further note that police units complained that “a previously useful tool now delivered results of limited benefit”.

Wider Implementation Proposals

Meanwhile, the government has launched a ten-week public review on its proposals to expand the use of facial recognition technology. The minister for police Sarah Jones has labeled the tool as the “biggest breakthrough since DNA matching”.

Expert and Oversight Concerns

Abimbola Johnson, head of the independent scrutiny and oversight board for the police race action plan, commented: “There was very little discussion in race action plan meetings of the facial recognition rollout despite clear relevance with the plan’s concerns.

“This disclosure demonstrate yet again that the pledges to combat discrimination the police has made through the equality initiative are not being translated into wider practice. Our reports have cautioned that innovative tools are being rolled out in a context where ethnic inequalities, weak scrutiny and poor data collection already persist.

“Any use of this technology must meet rigorous official guidelines, be subject to external review, and prove it diminishes rather than exacerbates ethnic bias.”

Home Office Response

A government representative stated: “The Home Office takes the conclusions of the report seriously and we have already taken action. A new algorithm has been independently tested and acquired, which has demonstrated no measurable discrimination. It will be trialled early next year and will be undergo further assessment.

“Our priority is protecting the public. This gamechanging technology will support officers to put criminals and rapists behind bars. There is human involvement in each stage of the procedure and no arrest or charge would be pursued without trained officers meticulously examining the output.”