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Law enforcement agencies across the United Kingdom successfully lobbied to use a facial recognition system known to be discriminatory against females, young people, and members of minority ethnic backgrounds, after complaining that a less biased version generated a reduced number of investigative leads.

How the System Works

British police use the police national database (PND) to carry out searches using historical face recognition. This process involves comparing a reference photograph of a person of interest against a repository of over 19 million custody photos to identify possible hits.

Acknowledged Discrimination

The UK interior ministry admitted last week that the technology was biased. This admission came after a study 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 said it “had acted on the findings”.

“It prompts the question of whether facial recognition only becomes effective if users tolerate discrimination in ethnicity and gender. Convenience is a poor argument for disregarding basic freedoms.”

Long-Standing Problem

Official papers reveal that this bias has been recognized for more than a year. Furthermore, police forces lobbied to reverse an earlier ruling that was intended to address the problem.

Senior officers were informed of the system's bias in late 2024. The government-ordered NPL review concluded the system was had a higher probability to produce false positives for images depicting women, individuals of Black ethnicity, and those aged 40 and under.

A Reversed Decision

In reaction, the national police leadership body mandated that the accuracy setting required for possible hits be increased to a point where the bias was greatly diminished.

However, this decision was overturned the next month after forces complained that the adjusted system was producing fewer “useful lines of inquiry”. NPCC documents indicate the higher threshold reduced the proportion of queries resulting in potential matches from 56% to a just under 15%.

Profound Inequalities

Although the authorities declined to specify what setting is currently used, the latest NPL study found the system could generate incorrect matches for women of Black heritage nearly a hundred times more often than for white women at certain settings.

The ministry commented on these results: “The testing identified that in a specific scenarios the software is has a greater tendency to incorrectly include some population segments in its match reports.”

Operational Effectiveness vs. Bias

Outlining the impact of the brief increase to the system's confidence threshold, the NPCC documents note: “This adjustment greatly lessens the effect of bias across legally safeguarded attributes of race, age and sex but had a significant negative impact on operational effectiveness”. The papers add that forces complained that “a once effective tactic now delivered outcomes of questionable value”.

Broader Rollout Plans

Meanwhile, the government has launched a ten-week consultation on its plans to widen the use of biometric scanning systems. Policing minister Sarah Jones has labeled the technology as the “most significant advance since DNA matching”.

Expert and Oversight Concerns

Abimbola Johnson, head of the advisory panel for the police race action plan, commented: “We observed very little discussion through race action plan meetings of the technology deployment despite clear relevance with the strategy's goals.

“These revelations show once again that the pledges to combat discrimination the police has made through the equality initiative are failing to be integrated into wider practice. Our reports have warned that innovative tools are being rolled out in a landscape where racial disparities, inadequate oversight and faulty information gathering already persist.

“All deployment of facial recognition must meet strict national standards, be independently scrutinised, and prove it reduces rather than exacerbates ethnic bias.”

Official Statement

A Home Office spokesperson stated: “We takes the findings of the report seriously and we have already taken action. A new algorithm has been externally evaluated and acquired, which has no statistically significant bias. It will be trialled early next year and will be undergo evaluation.

“The foremost aim is protecting the public. This revolutionary tool will assist officers to apprehend and prosecute offenders. There is officer review in every step of the process and no arrest or charge would be taken without trained officers meticulously examining the results.”