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Police forces across the UK effectively campaigned to use a facial recognition system acknowledged as discriminatory against females, youths, and individuals from ethnic minority groups, following complaints that a more accurate version generated a reduced number of investigative leads.

How the System Works

British police use the police national database (PND) to conduct searches using historical face recognition. This process entails comparing a “probe image” of a suspect against a database of over 19 million custody photos to find possible hits.

Admitted Bias

The Home Office conceded last week that the system was flawed. This admission followed a review by the government's National Physical Laboratory determined it incorrectly matched Black and Asian people and women at much greater frequency than white men. The ministry stated it “had acted on the findings”.

“It prompts the question of whether this technology only becomes effective if users accept biases in ethnicity and sex. Operational ease is a weak argument for disregarding fundamental rights.”

Known Issue

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

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

A Reversed Decision

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

However, this directive was reversed the next month after forces complained that the modified technology was generating fewer “useful lines of inquiry”. NPCC documents indicate the stricter setting reduced the number of searches that yielded possible identifications from 56% to a mere 14%.

Profound Inequalities

Although the authorities refused to say what setting is currently used, the latest independent review found the system could generate incorrect matches for women of Black heritage almost 100 times more frequently than for Caucasian women at certain settings.

The Home Office stated on these findings: “The testing found that in a specific scenarios the software is more likely to wrongly flag some demographic groups in its search results.”

Operational Effectiveness vs. Bias

Describing the impact of the brief increase to the system's confidence threshold, the police records note: “The change greatly lessens the impact of bias across legally safeguarded attributes of race, age and sex but had a significant negative impact on operational effectiveness”. The papers further note that police units complained that “a once effective tactic now delivered results of questionable value”.

Wider Implementation Proposals

Meanwhile, the UK administration has opened a ten-week consultation on its proposals 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 DNA matching”.

Expert and Oversight Concerns

Abimbola Johnson, head of the independent scrutiny and oversight board for the police race action plan, said: “There was scant discussion through race action plan meetings of the facial recognition rollout even with clear relevance with the strategy's goals.

“This disclosure show once again that the pledges to combat discrimination the police has undertaken via the race action plan are not being translated into wider practice. Independent assessments have cautioned that innovative tools are being rolled out in a landscape where racial disparities, weak scrutiny and poor data collection already persist.

“Any use of this technology must adhere to strict national standards, be subject to external review, and prove it diminishes rather than exacerbates ethnic bias.”

Home Office Response

A Home Office spokesperson said: “The Home Office treat the conclusions 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 undergo further assessment.

“Our priority is ensuring public safety. This revolutionary tool will support police to apprehend and prosecute offenders. There is human involvement in each stage of the procedure and no further action would be taken without specialist personnel carefully reviewing the results.”