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Law enforcement agencies across the United Kingdom effectively campaigned to deploy a facial recognition system acknowledged as discriminatory against women, young people, and individuals from minority ethnic backgrounds, after complaining that a less biased version produced fewer investigative leads.

How the System Works

British police utilize the police national database (PND) to conduct retrospective facial recognition searches. This process involves comparing 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 biased. This acknowledgment came after a study by the National Physical Laboratory (NPL) found it incorrectly matched Black and Asian people and women at much greater frequency than white men. The Home Office stated it “had acted on the findings”.

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

Long-Standing Problem

Official papers reveal that this bias has been recognized for over twelve months. Furthermore, police forces lobbied to reverse an initial decision that was designed to mitigate the problem.

Senior officers were informed of the system's bias in late 2024. The Home Office-commissioned NPL review found the system was more likely to suggest false positives for photos of females, individuals of Black ethnicity, and those aged 40 and under.

A Policy U-Turn

In response, the national police leadership body mandated that the accuracy setting required for possible hits be raised to a point where the disparity was greatly diminished.

However, this directive was reversed the next month after forces complained that the adjusted system was producing fewer “useful lines of inquiry”. NPCC documents show the stricter setting cut the proportion of searches that yielded potential matches from 56% to a mere under 15%.

Profound Inequalities

Although the authorities declined to specify what setting is now in operation, the recent independent review found the system could produce incorrect matches for women of Black heritage nearly a hundred times more often than for white women at specific configurations.

The ministry commented on these results: “The testing found that in a specific scenarios the algorithm is has a greater tendency to incorrectly include some population segments in its search results.”

Operational Effectiveness vs. Bias

Describing the impact 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 race, age and sex but had a substantially detrimental effect on police efficiency”. The papers further note 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 expand the use of facial recognition technology. The minister for police the relevant minister has described the technology as the “most significant advance since genetic fingerprinting”.

Criticism from Advisors and Monitors

The chair of a police oversight board, head of the independent scrutiny and oversight board for the national policing equality strategy, said: “We observed very little discussion through race action plan meetings of the technology deployment even with clear relevance with the strategy's goals.

“These revelations demonstrate yet again that the pledges to combat discrimination policing has undertaken via the equality initiative are failing to be integrated into broader operations. Our reports have warned that new technologies are being rolled out in a landscape where racial disparities, inadequate oversight and poor data collection already persist.

“All deployment of this technology must adhere to rigorous official guidelines, be independently scrutinised, and prove it diminishes rather than compounds ethnic bias.”

Home Office Response

A Home Office spokesperson stated: “The Home Office treat 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 in the coming months and will be undergo further assessment.

“The foremost aim is ensuring public safety. This gamechanging technology will support police to put criminals and rapists behind bars. There is human involvement in every step of the procedure and no further action would be pursued without specialist personnel carefully reviewing the output.”