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Police forces across the United Kingdom effectively campaigned to use a facial recognition system known to be biased against females, young people, and individuals from ethnic minority groups, after complaining that a more accurate version produced a reduced number of potential suspects.

How the System Works

UK forces utilize the police national database (PND) to carry out searches using historical face recognition. This process entails matching a “probe image” of a suspect against a repository of over 19 million mugshots to identify potential matches.

Admitted Bias

The Home Office conceded last week that the technology was flawed. This acknowledgment followed a review by the government's National Physical Laboratory determined it misidentified Black and Asian people and females at much greater frequency than white men. The Home Office stated it “took steps on the findings”.

“It prompts the question of whether facial recognition only becomes useful if users tolerate biases in race and sex. Operational ease is a poor argument for overriding basic freedoms.”

Known Issue

Official papers show that this bias has been recognized for over twelve months. Furthermore, law enforcement lobbied to reverse an initial decision that was intended to mitigate the problem.

Police bosses were informed of the system's bias in late 2024. The government-ordered laboratory study concluded the system was had a higher probability to produce false positives for images depicting women, individuals of Black ethnicity, and those aged 40 and under.

A Reversed Decision

In response, the National Police Chiefs’ Council (NPCC) mandated that the accuracy setting required for possible hits be raised to a level where the disparity was significantly reduced.

However, this directive was overturned the next month following complaints from police that the modified technology was generating a lower number of “useful lines of inquiry”. Internal records show the higher threshold cut the number of searches resulting in possible identifications from over half to a mere under 15%.

Profound Inequalities

Although the Home Office and NPCC refused to say what threshold is now in operation, the latest independent review found the system could produce false positives for women of Black heritage nearly a hundred times more often than for white women at certain settings.

The Home Office stated on these results: “The testing found that in a specific scenarios the software 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 NPCC documents note: “This adjustment significantly reduces the effect of bias across legally safeguarded attributes of ethnicity, age and gender but had a significant negative impact on operational effectiveness”. The papers further note that police units complained that “a previously useful tool now delivered outcomes of limited benefit”.

Broader Rollout Plans

Meanwhile, the government has opened a ten-week consultation on its plans to expand the use of facial recognition technology. Policing minister the relevant minister has labeled the tool as the “most significant advance since genetic fingerprinting”.

Criticism from Advisors and Monitors

Abimbola Johnson, chair of the advisory panel for the national policing equality strategy, commented: “We observed scant consideration through race action plan meetings of the facial recognition rollout even with clear relevance with the plan’s concerns.

“These revelations demonstrate yet again that the anti-racism commitments policing has undertaken through the race action plan are not being translated into wider practice. Our reports have warned that innovative tools are being implemented in a context where racial disparities, weak scrutiny and poor data collection continue to exist.

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

Official Statement

A government representative said: “The Home Office takes the conclusions of the report 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 early next year and will be undergo further assessment.

“Our priority is ensuring public safety. This revolutionary tool will assist police to apprehend and prosecute offenders. There is human involvement in each stage of the process and no arrest or charge would be pursued without specialist personnel meticulously examining the output.”