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Law enforcement agencies across the UK effectively campaigned to deploy a facial recognition system known to be discriminatory against women, young people, and individuals from minority ethnic backgrounds, following complaints that a more accurate version produced fewer investigative leads.

The Technology in Practice

British police utilize the police national database (PND) to carry out retrospective facial recognition searches. This process entails comparing a reference photograph of a person of interest against a database of over 19 million custody photos to identify possible hits.

Acknowledged Discrimination

The Home Office conceded last week that the technology was biased. This acknowledgment came after a study 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 ministry said it “had acted on the findings”.

“This raises the issue of whether this technology only becomes effective if users accept discrimination in ethnicity and gender. Operational ease is a poor argument for overriding fundamental rights.”

Known Issue

Internal documents show that this discriminatory flaw has been recognized for over twelve months. Furthermore, police forces argued to overturn an initial decision that was intended to mitigate the problem.

Senior officers were notified of the system's bias in September 2024. The government-ordered NPL review concluded the system was more likely to suggest incorrect matches for photos of females, Black people, and those under 40 years old.

A Reversed Decision

In reaction, the national police leadership body mandated that the accuracy setting required for potential matches be increased to a level where the bias was significantly reduced.

However, this directive was overturned the following month following complaints from police that the adjusted system was producing fewer “investigative leads”. Internal records show the stricter setting reduced the number of searches that yielded potential matches from over half to a just under 15%.

Severe Disparities

Although the Home Office and NPCC refused to say what setting is currently used, the latest NPL study discovered the system could produce incorrect matches for Black women nearly a hundred times more often than for white women at specific configurations.

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

Operational Effectiveness vs. Bias

Outlining the impact of the brief increase to the system's accuracy setting, the NPCC documents state: “This adjustment greatly lessens the impact of discrimination across legally safeguarded attributes of race, generation and gender but had a substantially detrimental effect on operational effectiveness”. The papers further note that police units complained that “a once effective tactic returned results 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. The minister for police Sarah Jones has described the technology as the “most significant advance since genetic fingerprinting”.

Criticism from Advisors and Monitors

Abimbola Johnson, head of the advisory panel for the police race action plan, commented: “We observed very little discussion through equality strategy sessions of the facial recognition rollout despite clear relevance with the strategy's goals.

“This disclosure show once again that the pledges to combat discrimination policing has made via the race action plan are not being translated into wider practice. Our reports have warned that innovative tools are being implemented in a landscape where racial disparities, weak scrutiny and faulty information gathering already persist.

“All deployment of facial recognition must meet strict national standards, be subject to external review, and prove it reduces rather than exacerbates ethnic bias.”

Home Office Response

A government representative stated: “We treat the findings of the report with utmost gravity 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 early next year and will be undergo evaluation.

“Our priority is ensuring public safety. This gamechanging technology will support officers to put criminals and rapists behind bars. There is officer review in every step of the process and no arrest or charge would be pursued without specialist personnel carefully reviewing the output.”