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Police forces across the United Kingdom effectively campaigned to use a facial recognition system known to be biased against females, youths, and members of minority ethnic backgrounds, following complaints that a less biased version generated fewer investigative leads.

The Technology in Practice

British police utilize the national police database to conduct retrospective facial recognition searches. This procedure entails comparing a “probe image” of a suspect against a repository of over 19 million mugshots to find possible hits.

Acknowledged Discrimination

The UK interior ministry admitted last week that the system was biased. This admission came after a study by the government's National Physical Laboratory found it incorrectly matched Black and Asian people and women at significantly higher rates than Caucasian males. The Home Office said it “took steps on the findings”.

“It prompts the issue of whether facial recognition only becomes useful if users accept discrimination in race and sex. Operational ease is a weak argument for overriding fundamental rights.”

Known Issue

Official papers show that this discriminatory flaw has been recognized for more than a year. Furthermore, law enforcement lobbied to reverse an earlier ruling that was designed 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 more likely to produce false positives for images depicting women, individuals of Black ethnicity, and those aged 40 and under.

A Policy U-Turn

In reaction, the national police leadership body 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 following month after forces complained that the modified technology was producing a lower number of “investigative leads”. NPCC documents show the higher threshold reduced the proportion of queries that yielded possible identifications from 56% to a mere under 15%.

Severe Disparities

Although the authorities refused to say what setting is currently used, the latest independent review discovered the system could generate false positives for women of Black heritage nearly a hundred times more frequently than for Caucasian women at specific configurations.

The Home Office commented on these findings: “The testing found that in a specific scenarios the software is more likely to incorrectly include some population segments in its match reports.”

Balancing Utility and Fairness

Outlining the impact of the temporary raise to the system's accuracy setting, the police records note: “The change greatly lessens the effect of discrimination across legally safeguarded attributes of ethnicity, generation and sex but had a significant negative impact on police efficiency”. The papers add that police units complained that “a once effective tactic now delivered outcomes of limited benefit”.

Broader Rollout Plans

Meanwhile, the UK administration has launched a ten-week consultation on its plans to expand the use of biometric scanning systems. Policing minister Sarah Jones has described the technology as the “most significant advance since genetic fingerprinting”.

Expert and Oversight Concerns

Abimbola Johnson, chair of the advisory panel for the national policing equality strategy, commented: “There was scant discussion in equality strategy sessions of the technology deployment even with clear relevance with the plan’s concerns.

“These revelations show once again that the anti-racism commitments policing has undertaken via the equality initiative are failing to be integrated into broader operations. Our reports have cautioned that innovative tools are being implemented in a landscape where ethnic inequalities, weak scrutiny and faulty information gathering continue to exist.

“Any use of this technology must meet strict national standards, be subject to external review, and prove it reduces rather than exacerbates racial disparity.”

Home Office Response

A government representative stated: “We treat the conclusions of the report with utmost gravity and we have already taken action. A new algorithm has been externally evaluated and acquired, which has demonstrated no measurable discrimination. It will be trialled early next year and will be subject to further assessment.

“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 process and no further action would be pursued without trained officers carefully reviewing the output.”