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Police forces across the UK successfully lobbied to use a facial recognition system known to be discriminatory against females, youths, and members of ethnic minority groups, following complaints that a more accurate version produced fewer investigative leads.

How the System Works

British police utilize the police national database (PND) to conduct retrospective facial recognition searches. This procedure involves matching a reference photograph of a person of interest against a database of more than 19 million mugshots to find potential matches.

Acknowledged Discrimination

The UK interior ministry conceded last week that the technology was flawed. This acknowledgment followed a review by the government's National Physical Laboratory determined it misidentified people of Black and Asian heritage and females at significantly higher rates than Caucasian males. The Home Office said it “had acted on the findings”.

“This raises the issue of whether this technology only becomes useful if users tolerate biases in ethnicity and gender. Convenience is a poor argument for disregarding basic freedoms.”

Long-Standing Problem

Official papers reveal that this discriminatory flaw has been known about for more than a year. Furthermore, police forces argued to overturn an initial decision that was designed to address the problem.

Senior officers were informed of the system's bias in September 2024. The Home Office-commissioned NPL review concluded the system was had a higher probability to produce false positives for images depicting women, individuals of Black ethnicity, 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 raised to a point where the bias was significantly reduced.

However, this decision was overturned the following month after forces complained that the adjusted system was producing fewer “investigative leads”. Internal records indicate the stricter setting reduced the number of queries resulting in possible identifications from over half to a mere 14%.

Severe Disparities

Although the authorities declined to specify what threshold is now in operation, the latest independent review discovered the system could generate false positives for women of Black heritage almost 100 times more often than for white women at specific configurations.

The ministry stated on these results: “Our evaluation found that in a specific scenarios the algorithm is has a greater tendency to incorrectly include some demographic groups in its search results.”

Balancing Utility and Fairness

Describing the effect of the brief increase to the system's accuracy setting, the NPCC documents note: “The change significantly reduces the effect of discrimination across protected characteristics of ethnicity, age and sex but had a significant negative impact on operational effectiveness”. The documents add that police units complained that “a once effective tactic returned results of questionable value”.

Broader Rollout Plans

Meanwhile, the UK administration has opened a ten-week consultation on its proposals to widen the use of facial recognition technology. Policing minister 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 scant discussion through race action plan meetings of the technology deployment despite obvious cross-over with the strategy's goals.

“This disclosure demonstrate yet again that the anti-racism commitments policing has undertaken through the race action plan are failing to be integrated into broader operations. Independent assessments have warned that new technologies are being implemented in a context where ethnic inequalities, weak scrutiny and poor data collection already persist.

“Any use of this technology must meet strict national standards, be independently scrutinised, and prove it diminishes rather than compounds ethnic bias.”

Home Office Response

A Home Office spokesperson said: “We treat the conclusions of the report with utmost gravity 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 protecting the public. This gamechanging technology will support police to apprehend and prosecute offenders. There is human involvement in every step of the process and no arrest or charge would be pursued without trained officers carefully reviewing the output.”