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Police forces across the United Kingdom effectively campaigned to deploy a face scanning system known to be biased against females, young people, and members of minority ethnic backgrounds, following complaints that a less biased version generated fewer potential suspects.

The Technology in Practice

British police utilize the national police database to conduct searches using historical face recognition. This procedure involves comparing a reference photograph of a suspect against a repository of more than 19 million mugshots to find possible hits.

Acknowledged Discrimination

The Home Office admitted last week that the system was biased. This admission came after a study by the government's National Physical Laboratory determined it misidentified Black and Asian people and women at significantly higher rates than white men. The Home Office stated it “took steps on the findings”.

“This raises the question of whether facial recognition only becomes useful if users accept discrimination in race and gender. Convenience is a weak argument for overriding fundamental rights.”

Known Issue

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

Senior officers were notified of the system's bias in September 2024. The Home Office-commissioned NPL review found the system was more likely to suggest false positives for photos of women, Black people, and those under 40 years old.

A Policy U-Turn

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

However, this decision was reversed the next month after forces complained that the modified technology was producing a lower number of “useful lines of inquiry”. NPCC documents indicate the stricter setting reduced the number of queries resulting in potential matches from over half to a mere under 15%.

Profound Inequalities

Although the authorities declined to specify what threshold is now in operation, the latest NPL study discovered the system could produce false positives for women of Black heritage nearly a hundred times more frequently than for Caucasian women at certain settings.

The Home Office stated on these findings: “Our evaluation identified that in a limited set of circumstances the software is has a greater tendency to wrongly flag some demographic groups in its match reports.”

Operational Effectiveness vs. Bias

Outlining the effect of the temporary raise to the system's accuracy setting, the police records note: “This adjustment significantly reduces the effect of bias across protected characteristics of race, generation and gender but had a significant negative impact on operational effectiveness”. The papers add that police units complained that “a previously useful tool returned results of limited benefit”.

Broader Rollout Plans

Meanwhile, the UK administration has launched a ten-week public review on its plans to expand the use of facial recognition technology. Policing minister Sarah Jones has described the technology as the “biggest breakthrough since genetic fingerprinting”.

Criticism from Advisors and Monitors

The chair of a police oversight board, chair of the advisory panel for the police race action plan, commented: “We observed very little consideration through equality strategy sessions of the facial recognition rollout despite obvious cross-over with the strategy's goals.

“These revelations show yet again that the pledges to combat discrimination policing has made via the equality initiative are failing to be integrated into broader operations. Independent assessments have cautioned that innovative tools are being rolled out in a context where ethnic inequalities, inadequate oversight and faulty information gathering already persist.

“All deployment of facial recognition must meet strict national standards, be independently scrutinised, and demonstrate it diminishes rather than compounds racial disparity.”

Official Statement

A Home Office spokesperson stated: “We treat the findings of the report with utmost gravity and we have implemented changes. A updated software has been externally evaluated and procured, which has no statistically significant bias. It will be trialled in the coming months and will be subject to further assessment.

“The foremost aim is ensuring public safety. This revolutionary tool will assist officers to apprehend and prosecute offenders. There is officer review in every step of the procedure and no further action would be pursued without specialist personnel meticulously examining the output.”