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Police forces across the UK effectively campaigned to deploy 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 investigative leads.

The Technology in Practice

UK forces utilize the police national database (PND) to carry out searches using historical face recognition. This procedure involves matching a “probe image” of a person of interest against a repository of over 19 million mugshots to identify possible hits.

Admitted Bias

The UK interior ministry conceded last week that the technology was biased. This admission followed a study by the government's National Physical Laboratory determined it incorrectly matched people of Black and Asian heritage and females at much greater frequency than white men. The ministry said it “took steps on the findings”.

“It prompts the issue of whether this technology only becomes useful if users accept biases in race and sex. Convenience is a weak argument for overriding basic freedoms.”

Long-Standing Problem

Official papers show that this discriminatory flaw has been recognized for more than a year. Furthermore, law enforcement lobbied to reverse an initial decision that was intended to mitigate the problem.

Senior officers were notified of the system's bias in late 2024. The government-ordered NPL review found the system was had a higher probability to suggest false positives 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 increased to a level where the disparity was significantly reduced.

However, this directive was reversed the next month following complaints from police that the adjusted system was generating a lower number of “useful lines of inquiry”. Internal records show the stricter setting reduced the proportion of searches that yielded possible identifications from 56% to a mere 14%.

Severe Disparities

Although the authorities declined to specify what threshold is now in operation, the recent NPL study discovered the system could generate incorrect matches for Black women nearly a hundred times more often than for Caucasian women at specific configurations.

The Home Office commented on these results: “The testing identified that in a limited set of circumstances the algorithm is has a greater tendency to wrongly flag some demographic groups in its match reports.”

Operational Effectiveness vs. Bias

Describing the effect of the temporary raise to the system's accuracy setting, the police records note: “The change significantly reduces the effect of bias across legally safeguarded attributes of ethnicity, generation and sex but had a significant negative impact on police efficiency”. The papers add that forces argued that “a once effective tactic returned results of limited benefit”.

Broader Rollout Plans

Meanwhile, the government has opened a ten-week public review on its proposals to widen the use of biometric scanning systems. Policing minister Sarah Jones has described the technology as the “most significant advance since genetic fingerprinting”.

Expert and Oversight Concerns

Abimbola Johnson, chair of the advisory panel for the police race action plan, said: “There was scant discussion through equality strategy sessions of the technology deployment even with clear relevance with the plan’s concerns.

“This disclosure show yet again that the anti-racism commitments policing has made through the race action plan are failing to be integrated into wider practice. Our reports have cautioned that new technologies are being implemented in a landscape where racial disparities, inadequate oversight and faulty information gathering continue to exist.

“All deployment of this technology must meet rigorous official guidelines, be independently scrutinised, and demonstrate it diminishes rather than exacerbates ethnic bias.”

Home Office Response

A Home Office spokesperson stated: “We takes the findings of the report with utmost gravity and we have implemented changes. A updated software has been externally evaluated and acquired, which has no statistically significant bias. It will be tested early next year and will be subject to further assessment.

“The foremost aim is ensuring public safety. This revolutionary tool will support police to put criminals and rapists behind bars. There is officer review in each stage of the process and no further action would be pursued without trained officers meticulously examining the output.”