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Police forces across the United Kingdom effectively campaigned to use a facial recognition system acknowledged as biased against females, young people, and individuals from minority ethnic backgrounds, after complaining that a more accurate version produced fewer investigative leads.

How the System Works

UK forces utilize the national police database to carry out searches using historical face recognition. This procedure entails comparing a “probe image” of a suspect against a database of over 19 million custody photos to find potential matches.

Acknowledged Discrimination

The Home Office admitted last week that the system was flawed. This admission came after a study by the National Physical Laboratory (NPL) found it misidentified people of Black and Asian heritage and women at much greater frequency than white men. The ministry said it “had acted on the findings”.

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

Long-Standing Problem

Internal documents reveal that this discriminatory flaw has been known about for more than a year. Furthermore, police forces argued to overturn an earlier ruling that was intended to mitigate the problem.

Senior officers were informed of the algorithmic discrimination in late 2024. The government-ordered laboratory study concluded the system was had a higher probability to produce 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 increased to a level where the disparity was significantly reduced.

However, this directive was reversed the following month following complaints from police that the adjusted system was producing fewer “useful lines of inquiry”. Internal records show the stricter setting cut the number of searches resulting in potential matches from over half to a just under 15%.

Profound Inequalities

Although the Home Office and NPCC declined to specify what setting is currently used, the latest independent review found the system could produce incorrect matches for women of Black heritage almost 100 times more frequently than for white women at specific configurations.

The ministry stated on these results: “The testing identified that in a limited set of circumstances the software is more likely to wrongly flag some population segments in its match reports.”

Operational Effectiveness vs. Bias

Describing the effect of the temporary raise to the system's confidence threshold, the police records state: “This adjustment significantly reduces the impact of discrimination across legally safeguarded attributes of race, generation and sex but had a significant negative impact on operational effectiveness”. The papers add that police units complained that “a previously useful tool returned outcomes of limited benefit”.

Wider Implementation Proposals

Meanwhile, the UK administration has opened a ten-week consultation on its proposals to expand the use of facial recognition technology. Policing minister the relevant minister has described the tool as the “biggest breakthrough since genetic fingerprinting”.

Expert and Oversight Concerns

Abimbola Johnson, chair of the independent scrutiny and oversight board for the national policing equality strategy, said: “There was scant discussion through race action plan meetings of the facial recognition rollout even with clear relevance with the strategy's goals.

“This disclosure show once again that the pledges to combat discrimination policing has undertaken via the equality initiative are failing to be integrated into broader operations. Independent assessments have cautioned that new technologies are being implemented in a landscape where racial disparities, weak scrutiny and poor data collection continue to exist.

“Any use of this technology must meet rigorous official guidelines, be subject to external review, and prove it diminishes rather than compounds ethnic bias.”

Home Office Response

A government representative stated: “We takes the conclusions of the report seriously and we have already taken action. A new algorithm has been externally evaluated and acquired, which has demonstrated no measurable discrimination. It will be tested in the coming months and will be undergo evaluation.

“The foremost aim is ensuring public safety. This revolutionary tool will assist police 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.”