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Police forces across the United Kingdom effectively campaigned to use a facial recognition system acknowledged as discriminatory against females, youths, and individuals from minority ethnic backgrounds, following complaints that a more accurate version produced fewer potential suspects.

How the System Works

British police utilize the police national database (PND) to conduct retrospective facial recognition searches. This process entails comparing a reference photograph of a person of interest against a database of more than 19 million custody photos to find potential matches.

Admitted Bias

The Home Office admitted last week that the technology was flawed. This admission followed a study by the government's National Physical Laboratory found it misidentified Black and Asian people and females at significantly higher rates than Caucasian males. The ministry said it “had acted on the findings”.

“This raises the question of whether facial recognition only becomes effective if users accept discrimination in ethnicity and sex. Convenience is a poor argument for overriding fundamental rights.”

Known Issue

Internal documents reveal that this bias has been known about for over twelve months. Furthermore, law enforcement argued to overturn an earlier ruling that was intended to address the problem.

Senior officers were notified of the algorithmic discrimination in late 2024. The government-ordered laboratory study concluded the system was more likely to suggest false positives for photos of women, individuals of Black ethnicity, and those under 40 years old.

A Reversed Decision

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

However, this directive was reversed the next month following complaints from police that the adjusted system was producing fewer “investigative leads”. Internal records indicate the stricter setting reduced the number of searches that yielded potential matches from 56% to a mere under 15%.

Severe Disparities

Although the authorities declined to specify what threshold is now in operation, the recent independent review found the system could produce incorrect matches for Black women almost 100 times more often than for white women at specific configurations.

The ministry commented on these findings: “Our evaluation found 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

Outlining the impact of the temporary raise to the system's accuracy setting, the NPCC documents state: “This adjustment significantly reduces the effect of bias across protected characteristics of ethnicity, generation and sex but had a substantially detrimental effect on operational effectiveness”. The documents further note that police units argued that “a previously useful tool returned outcomes of limited benefit”.

Broader Rollout Plans

Meanwhile, the UK administration has opened a ten-week consultation on its plans to widen the use of facial recognition technology. The minister for police the relevant minister has described the technology as the “biggest breakthrough since genetic fingerprinting”.

Expert and Oversight Concerns

Abimbola Johnson, head 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 facial recognition rollout even with clear relevance with the plan’s concerns.

“These revelations show yet again that the anti-racism commitments the police has made via the equality initiative are failing to be integrated into broader operations. Our reports have warned that innovative tools are being implemented in a landscape where racial disparities, weak scrutiny and poor data collection continue to exist.

“Any use of facial recognition must adhere to rigorous official guidelines, be subject to external review, and prove it reduces rather than exacerbates ethnic bias.”

Official Statement

A government representative said: “We treat the findings of the study seriously and we have already taken action. A new algorithm has been externally evaluated and procured, which has demonstrated no measurable discrimination. It will be tested early next year and will be subject to evaluation.

“The foremost aim is ensuring public safety. This gamechanging technology will support police to apprehend and prosecute offenders. There is human involvement in each stage of the procedure and no further action would be pursued without specialist personnel carefully reviewing the output.”