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Law enforcement agencies across the United Kingdom effectively campaigned to use a face scanning system acknowledged as discriminatory against women, young people, and members of ethnic minority groups, following complaints that a more accurate version generated a reduced number of investigative leads.

How the System Works

British police use the national police database to carry out retrospective facial recognition searches. This process involves matching a reference photograph of a person of interest against a repository of over 19 million custody photos to find potential matches.

Admitted Bias

The Home Office admitted last week that the technology was biased. This admission came after a study by the government's National Physical Laboratory found it misidentified people of Black and Asian heritage and females at much greater frequency than white men. The ministry stated it “took steps on the findings”.

“It prompts the question of whether this technology only becomes useful if users tolerate biases in ethnicity and sex. Convenience is a weak argument for disregarding basic freedoms.”

Known Issue

Official papers show that this bias has been recognized 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 Home Office-commissioned NPL review found the system was more likely to produce false positives for images depicting women, individuals of Black ethnicity, and those aged 40 and under.

A Policy U-Turn

In reaction, the national police leadership body ordered that the confidence threshold required for possible hits be raised to a level where the bias was greatly diminished.

However, this directive was reversed the following month after forces complained that the adjusted system was producing fewer “investigative leads”. Internal records show the stricter setting reduced the proportion of searches that yielded possible identifications from over half to a mere 14%.

Profound Inequalities

Although the authorities declined to specify what setting is currently used, the recent NPL study discovered the system could produce false positives for Black women almost 100 times more frequently than for Caucasian women at specific configurations.

The Home Office commented on these findings: “The testing identified that in a specific scenarios the software is more likely to wrongly flag some population segments in its match reports.”

Operational Effectiveness vs. Bias

Describing the impact of the brief increase to the system's confidence threshold, the police records state: “This adjustment greatly lessens the impact of discrimination across legally safeguarded attributes of race, generation and gender but had a significant negative impact on police efficiency”. The papers add that police units argued that “a once effective tactic now delivered outcomes of questionable value”.

Broader Rollout Plans

Meanwhile, the government has opened a two-and-a-half-month 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 genetic fingerprinting”.

Criticism from Advisors and Monitors

The chair of a police oversight board, chair of the advisory panel for the police race action plan, said: “We observed scant consideration in equality strategy sessions of the facial recognition rollout despite obvious cross-over with the strategy's goals.

“These revelations show yet again that the anti-racism commitments the police has undertaken via the race action plan are not being translated into broader operations. Independent assessments have warned that innovative tools are being rolled out in a context where ethnic inequalities, inadequate oversight and faulty information gathering continue to exist.

“Any use of facial recognition must adhere to strict national standards, be independently scrutinised, and demonstrate it diminishes rather than exacerbates racial disparity.”

Official Statement

A Home Office spokesperson stated: “The Home Office takes the findings of the study with utmost gravity and we have already taken action. A updated software has been externally evaluated and acquired, which has no statistically significant bias. It will be tested early next year and will be subject to evaluation.

“Our priority is protecting the public. This revolutionary tool will support officers to put criminals and rapists behind bars. There is officer review in every step of the process and no further action would be pursued without specialist personnel carefully reviewing the results.”