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Police forces across the UK successfully lobbied to use a facial recognition system acknowledged as biased against females, young people, and individuals from ethnic minority groups, following complaints that a more accurate version produced fewer investigative leads.

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 reference photograph of a suspect against a repository of over 19 million custody photos to identify potential matches.

Acknowledged Discrimination

The UK interior ministry conceded last week that the technology was flawed. This admission came after a review by the government's National Physical Laboratory found it incorrectly matched people of Black and Asian heritage and women at significantly higher rates than Caucasian males. The Home Office stated it “had acted on the findings”.

“This raises the issue of whether facial recognition only becomes useful if users accept biases in race and sex. Convenience is a weak argument for overriding basic freedoms.”

Known Issue

Official papers reveal that this discriminatory flaw has been known about for over twelve months. Furthermore, police forces argued to overturn an earlier ruling that was designed to address the problem.

Senior officers were notified of the algorithmic discrimination in September 2024. The government-ordered laboratory study found the system was more likely to suggest incorrect matches for photos of females, individuals of Black ethnicity, and those under 40 years old.

A Reversed Decision

In response, the National Police Chiefs’ Council (NPCC) mandated that the confidence threshold required for potential matches be increased to a point where the disparity was significantly reduced.

However, this decision was reversed the next month following complaints from police that the modified technology was producing a lower number of “investigative leads”. NPCC documents indicate the higher threshold cut the number of searches resulting in possible identifications from 56% to a mere 14%.

Severe Disparities

Although the Home Office and NPCC declined to specify what setting 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 ministry stated on these results: “Our evaluation identified that in a specific scenarios the software is has a greater tendency to wrongly flag some population segments in its match reports.”

Operational Effectiveness vs. Bias

Outlining the effect of the brief increase to the system's accuracy setting, the NPCC documents note: “The change significantly reduces the impact of bias across protected characteristics of race, generation and sex but had a significant negative impact on police efficiency”. The documents further note that forces complained that “a once effective tactic returned results of limited benefit”.

Wider Implementation Proposals

Meanwhile, the UK administration has opened a ten-week consultation on its proposals to expand the use of biometric scanning systems. The minister for police the relevant minister has described the tool as the “biggest breakthrough since genetic fingerprinting”.

Criticism from Advisors and Monitors

Abimbola Johnson, head of the advisory panel for the national policing equality strategy, commented: “We observed scant consideration through race action plan meetings of the technology deployment even with clear relevance with the strategy's goals.

“These revelations show yet again that the pledges to combat discrimination policing has made through the race action plan are not being translated into wider practice. Our reports have cautioned that innovative tools are being implemented in a landscape where ethnic inequalities, weak scrutiny and faulty information gathering already persist.

“All deployment of this technology must meet strict national standards, be independently scrutinised, and demonstrate it diminishes rather than exacerbates ethnic bias.”

Home Office Response

A Home Office spokesperson stated: “The Home Office takes the findings of the report with utmost gravity and we have implemented changes. A updated software has been externally evaluated and procured, which has demonstrated no measurable discrimination. It will be trialled early next year and will be subject to evaluation.

“The foremost aim is ensuring public safety. This revolutionary tool will support officers to apprehend and prosecute offenders. There is human involvement in each stage of the procedure and no arrest or charge would be pursued without trained officers meticulously examining the output.”