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Police forces across the UK successfully lobbied to use a facial recognition system known to be biased against women, youths, and members of ethnic minority groups, after complaining that a less biased version produced a reduced number of investigative leads.

How the System Works

British police use the national police database to carry out retrospective facial recognition searches. This process entails comparing a reference photograph of a suspect against a repository of more than 19 million mugshots to find potential matches.

Acknowledged Discrimination

The Home Office conceded last week that the technology was biased. This admission came after a review by the government's National Physical Laboratory determined it misidentified people of Black and Asian heritage and women at significantly higher rates than Caucasian males. The Home Office said it “took steps on the findings”.

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

Known Issue

Internal documents reveal that this bias has been recognized 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 Home Office-commissioned laboratory study found the system was had a higher probability to produce false positives for images depicting females, Black people, and those aged 40 and under.

A Reversed Decision

In response, the national police leadership body mandated that the accuracy setting required for possible hits be raised to a point where the disparity was significantly reduced.

However, this decision was overturned the next month after forces complained that the modified technology was producing a lower number of “investigative leads”. NPCC documents show the stricter setting cut the proportion 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 now in operation, the latest independent review found the system could generate false positives for women of Black heritage nearly a hundred times more frequently than for Caucasian women at certain settings.

The ministry stated on these findings: “The testing identified that in a specific scenarios the software is more likely to incorrectly include some demographic groups in its search results.”

Balancing Utility and Fairness

Outlining the effect of the brief increase to the system's accuracy setting, the police records note: “This adjustment greatly lessens the impact of discrimination across protected characteristics of race, age and gender but had a significant negative impact on operational effectiveness”. The documents add that police units argued that “a previously useful tool now delivered results of questionable value”.

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 the relevant minister has labeled the technology as the “most significant advance since DNA matching”.

Criticism from Advisors and Monitors

The chair of a police oversight board, chair of the independent scrutiny and oversight board for the national policing equality strategy, commented: “We observed very little discussion in race action plan meetings of the technology deployment despite obvious cross-over with the plan’s concerns.

“This disclosure demonstrate once again that the anti-racism commitments the police has made through the race action plan are not being translated into broader operations. Our reports have cautioned that new technologies are being rolled out in a landscape where ethnic inequalities, weak scrutiny and poor data collection continue to exist.

“All deployment of facial recognition must adhere to rigorous official guidelines, be subject to external review, and prove it diminishes rather than compounds ethnic bias.”

Home Office Response

A government representative stated: “The Home Office treat the findings of the report with utmost gravity and we have already taken action. A updated software has been independently tested and procured, which has no statistically significant bias. It will be trialled early next year and will be subject to further assessment.

“Our priority is ensuring public safety. This revolutionary tool will assist officers to put criminals and rapists behind bars. There is human involvement in every step of the process and no arrest or charge would be taken without trained officers meticulously examining the results.”