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Police forces across the United Kingdom successfully lobbied to use a facial recognition system known to be biased against women, youths, and individuals from minority ethnic backgrounds, after complaining that a more accurate version generated fewer investigative leads.

How the System Works

UK forces use the national police database to carry out searches using historical face recognition. This procedure entails comparing a reference photograph of a suspect against a repository of more than 19 million custody photos to identify possible hits.

Acknowledged Discrimination

The UK interior ministry conceded last week that the system was biased. This acknowledgment came after a review by the government's National Physical Laboratory found it misidentified people of Black and Asian heritage and women at much greater frequency than Caucasian males. The ministry said it “had acted on the findings”.

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

Long-Standing Problem

Official papers show that this discriminatory flaw has been known about for more than a year. Furthermore, law enforcement lobbied to reverse an initial decision that was intended to address the problem.

Senior officers were notified of the system's bias in late 2024. The government-ordered NPL review found the system was had a higher probability to produce incorrect matches for photos of women, individuals of Black ethnicity, and those under 40 years old.

A Policy U-Turn

In reaction, the national police leadership body mandated that the confidence threshold required for potential matches be increased to a level where the bias was greatly diminished.

However, this directive was reversed the next month after forces complained that the adjusted system was producing fewer “investigative leads”. Internal records indicate the stricter setting cut the proportion of queries that yielded possible identifications from 56% to a just 14%.

Profound Inequalities

Although the Home Office and NPCC refused to say what setting is currently used, the recent independent review found the system could produce false positives for Black women nearly a hundred times more frequently than for Caucasian women at certain settings.

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

Operational Effectiveness vs. Bias

Describing the effect of the brief increase to the system's confidence threshold, the police records note: “This adjustment significantly reduces the impact of bias across protected characteristics of race, age and gender but had a significant negative impact on police efficiency”. The documents further note that police units argued that “a previously useful tool now delivered outcomes of questionable value”.

Broader Rollout Plans

Meanwhile, the government has opened a ten-week consultation on its proposals to widen the use of facial recognition technology. The minister for police Sarah Jones has labeled the technology as the “biggest breakthrough since genetic fingerprinting”.

Criticism from Advisors and Monitors

Abimbola Johnson, chair of the independent scrutiny and oversight board for the police race action plan, commented: “There was very little discussion in race action plan meetings of the technology deployment even with clear relevance with the plan’s concerns.

“These revelations demonstrate yet again that the pledges to combat discrimination policing has made through the race action plan are failing to be integrated into wider practice. Our reports have cautioned that new technologies are being rolled out in a landscape where racial disparities, inadequate oversight and faulty information gathering already persist.

“All deployment of this technology must adhere to strict national standards, be independently scrutinised, and demonstrate it reduces rather than compounds racial disparity.”

Home Office Response

A Home Office spokesperson said: “The Home Office takes the conclusions of the study seriously and we have implemented changes. A updated software has been externally evaluated and procured, which has no statistically significant bias. It will be tested early next year and will be undergo evaluation.

“Our priority is ensuring public safety. This gamechanging technology will assist officers to put criminals and rapists behind bars. There is human involvement in every step of the process and no arrest or charge would be pursued without specialist personnel meticulously examining the output.”