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Police forces across the United Kingdom effectively campaigned to use a facial recognition system known to be discriminatory against females, youths, and members of ethnic minority groups, after complaining that a less biased version generated a reduced number of potential suspects.

How the System Works

UK forces use the police national database (PND) to conduct searches using historical face recognition. This procedure involves matching a “probe image” of a suspect against a database of more than 19 million mugshots to find possible hits.

Admitted Bias

The UK interior ministry conceded last week that the technology was flawed. This admission came after a study by the National Physical Laboratory (NPL) determined it incorrectly matched people of Black and Asian heritage and women at significantly higher rates than white men. The ministry said it “took steps on the findings”.

“This raises the issue of whether facial recognition only becomes useful if users accept biases 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 more than a year. Furthermore, police forces lobbied to reverse an initial decision that was intended to address the problem.

Senior officers were informed of the algorithmic discrimination in late 2024. The government-ordered laboratory study 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 Chiefs’ Council (NPCC) mandated that the accuracy setting required for potential matches be raised to a level where the bias was significantly reduced.

However, this directive was overturned the following month after forces complained that the adjusted system was generating fewer “useful lines of inquiry”. Internal records indicate the higher threshold reduced the number of searches resulting in possible identifications from 56% to a just 14%.

Profound Inequalities

Although the authorities refused to say what setting is currently used, 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 certain settings.

The Home Office stated on these results: “Our evaluation identified that in a limited set of circumstances the software is more likely to incorrectly include some demographic groups in its search results.”

Balancing Utility and Fairness

Outlining the impact of the temporary raise to the system's confidence threshold, the police records note: “The change significantly reduces the effect of discrimination across legally safeguarded attributes of ethnicity, age and sex but had a significant negative impact on operational effectiveness”. The documents further note that police units complained that “a previously useful tool returned results of questionable value”.

Wider Implementation Proposals

Meanwhile, the UK administration has launched a ten-week public review on its proposals to widen the use of facial recognition technology. The minister for police Sarah Jones has labeled the technology as the “biggest breakthrough 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, commented: “We observed scant discussion through race action plan meetings of the facial recognition rollout despite clear relevance with the strategy's goals.

“These revelations demonstrate yet again that the anti-racism commitments policing has made via the race action plan are not being translated into broader operations. Our reports have cautioned that new technologies are being implemented in a context where ethnic inequalities, weak scrutiny and poor data collection already persist.

“All deployment of facial recognition must meet strict national standards, be subject to external review, and demonstrate it diminishes rather than exacerbates racial disparity.”

Home Office Response

A government representative stated: “The Home Office takes the findings of the study seriously and we have already taken action. A updated software has been independently tested and procured, which has demonstrated no measurable discrimination. It will be trialled in the coming months and will be undergo evaluation.

“Our priority is protecting the public. This revolutionary tool will support police to put criminals and rapists behind bars. There is officer review in each stage of the procedure and no arrest or charge would be pursued without specialist personnel meticulously examining the results.”