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Law enforcement agencies across the United Kingdom effectively campaigned to use a face scanning system acknowledged as discriminatory against females, young people, and members of ethnic minority groups, after complaining that a less biased version produced a reduced number of investigative leads.

The Technology in Practice

UK forces use the police national database (PND) to carry out retrospective facial recognition searches. This procedure entails matching a “probe image” of a person of interest against a repository of more than 19 million mugshots to find possible hits.

Acknowledged Discrimination

The UK interior ministry conceded last week that the technology was biased. This admission followed a study by the government's National Physical Laboratory found it incorrectly matched Black and Asian people and women at much greater frequency than Caucasian males. The ministry stated it “took steps on the findings”.

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

Known Issue

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

Police bosses were informed 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 females, Black people, and those aged 40 and under.

A Policy U-Turn

In response, the national police leadership body mandated that the accuracy setting required for potential matches be raised to a point where the disparity was significantly reduced.

However, this directive was reversed the following month after forces complained that the adjusted system was producing fewer “useful lines of inquiry”. NPCC documents indicate the stricter setting reduced the proportion of searches that yielded possible identifications from over half to a just under 15%.

Severe Disparities

Although the Home Office and NPCC declined to specify what setting is now in operation, the latest independent review discovered the system could produce incorrect matches for women of Black heritage nearly a hundred times more often than for Caucasian women at certain settings.

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

Balancing Utility and Fairness

Describing the impact of the brief increase to the system's accuracy setting, the NPCC documents state: “The change greatly lessens the impact of bias across legally safeguarded attributes of race, age and sex but had a substantially detrimental effect on operational effectiveness”. The papers add that forces complained that “a once effective tactic now delivered results of limited benefit”.

Wider Implementation Proposals

Meanwhile, the government has launched a ten-week consultation on its plans to widen the use of facial recognition technology. Policing minister the relevant minister has labeled the tool as the “biggest breakthrough since DNA matching”.

Criticism from Advisors and Monitors

Abimbola Johnson, head of the independent scrutiny and oversight board for the national policing equality strategy, said: “There was scant discussion in equality strategy sessions of the facial recognition rollout despite obvious cross-over with the plan’s concerns.

“This disclosure show yet again that the pledges to combat discrimination policing has made through the equality initiative are failing to be integrated into wider practice. Independent assessments have warned that new technologies are being implemented in a context where racial disparities, weak scrutiny and poor data collection already persist.

“All deployment of this technology must adhere to strict national standards, be independently scrutinised, and prove it diminishes rather than compounds racial disparity.”

Official Statement

A government representative said: “We treat the findings of the study with utmost gravity and we have implemented changes. A new algorithm has been independently tested and procured, which has no statistically significant bias. It will be tested early next year and will be subject to evaluation.

“The foremost aim is protecting the public. This revolutionary tool will support officers to apprehend and prosecute offenders. There is officer review in each stage of the procedure and no arrest or charge would be taken without trained officers meticulously examining the results.”