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Law enforcement agencies across the United Kingdom successfully lobbied to deploy a face scanning system known to be discriminatory against women, young people, and members of ethnic minority groups, following complaints that a less biased version generated a reduced number of potential suspects.

The Technology in Practice

British police utilize the police national database (PND) to conduct retrospective facial recognition searches. This process entails comparing a reference photograph of a suspect against a database of more than 19 million mugshots to identify possible hits.

Admitted Bias

The UK interior ministry conceded last week that the system was biased. This acknowledgment followed a review by the National Physical Laboratory (NPL) determined it misidentified people of Black and Asian heritage and women at much greater frequency than Caucasian males. The Home Office stated it “took steps on the findings”.

“This raises the issue of whether facial recognition only becomes useful if users accept discrimination in ethnicity and sex. Convenience is a weak argument for disregarding fundamental rights.”

Known Issue

Official papers reveal that this discriminatory flaw has been recognized for over twelve months. Furthermore, law enforcement argued to overturn an earlier ruling that was intended to mitigate the problem.

Police bosses were notified of the algorithmic discrimination in late 2024. The Home Office-commissioned NPL review found the system was more likely to produce false positives for photos of women, Black people, and those under 40 years old.

A Policy U-Turn

In reaction, the National Police Chiefs’ Council (NPCC) mandated that the accuracy setting required for possible hits be increased to a point where the bias was significantly reduced.

However, this directive was reversed the next month after forces complained that the modified technology was producing a lower number of “investigative leads”. Internal records indicate the stricter setting reduced the proportion of searches that yielded possible identifications from 56% to a just 14%.

Profound Inequalities

Although the Home Office and NPCC declined to specify what threshold is currently used, the latest independent review discovered the system could generate incorrect matches for women of Black heritage nearly a hundred times more frequently than for Caucasian women at specific configurations.

The ministry commented on these results: “Our evaluation identified that in a limited set of circumstances the software is has a greater tendency to wrongly flag some population segments in its match reports.”

Balancing Utility and Fairness

Outlining the impact of the temporary raise to the system's accuracy setting, the NPCC documents note: “This adjustment greatly lessens the effect of bias across protected characteristics of race, age and sex but had a substantially detrimental effect on operational effectiveness”. The documents further note that forces complained that “a previously useful tool now delivered outcomes of limited benefit”.

Wider Implementation Proposals

Meanwhile, the government has launched a ten-week consultation on its proposals to expand the use of biometric scanning systems. The minister for police Sarah Jones has labeled the technology as the “biggest breakthrough since DNA matching”.

Criticism from Advisors and Monitors

Abimbola Johnson, head of the independent scrutiny and oversight board for the national policing equality strategy, said: “We observed very little 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 made via the equality initiative are not being translated into broader operations. Our reports have warned that innovative tools are being implemented in a landscape where ethnic inequalities, inadequate oversight and poor data collection already persist.

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

Official Statement

A Home Office spokesperson stated: “We takes the conclusions of the study seriously and we have already taken action. A updated software has been externally evaluated and acquired, which has demonstrated no measurable discrimination. It will be trialled early next year and will be undergo evaluation.

“Our priority is ensuring public safety. This gamechanging technology will assist officers to apprehend and prosecute offenders. There is human involvement in each stage of the procedure and no arrest or charge would be taken without trained officers meticulously examining the output.”