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Law enforcement agencies across the UK effectively campaigned to use a facial recognition system known to be biased against women, youths, and members of minority ethnic backgrounds, after complaining that a less biased version generated a reduced number of investigative leads.

The Technology in Practice

British police utilize the police national database (PND) to conduct searches using historical face recognition. This procedure entails matching a “probe image” of a suspect against a repository of over 19 million custody photos to identify potential matches.

Admitted Bias

The UK interior ministry conceded last week that the technology was flawed. This acknowledgment followed a study by the government's National Physical Laboratory found it misidentified Black and Asian people and women at much greater frequency than Caucasian males. The Home Office stated it “took steps on the findings”.

“It prompts the issue of whether this technology only becomes useful if users accept discrimination in race and sex. Operational ease is a weak argument for disregarding fundamental rights.”

Long-Standing Problem

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

Senior officers were notified of the system's bias in late 2024. The government-ordered laboratory study found the system was had a higher probability to produce false positives for images depicting women, Black people, and those aged 40 and under.

A Reversed Decision

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

However, this directive was reversed the next month following complaints from police that the adjusted system was generating a lower number of “investigative leads”. Internal records show the stricter setting reduced the number of searches that yielded potential matches from over half to a mere 14%.

Severe Disparities

Although the authorities refused to say what threshold is currently used, the recent independent review found the system could produce incorrect matches for Black women almost 100 times more frequently than for white women at specific configurations.

The ministry stated on these findings: “The testing found that in a limited set of circumstances the algorithm is has a greater tendency to wrongly flag some demographic groups in its search results.”

Operational Effectiveness vs. Bias

Outlining the impact of the brief increase to the system's accuracy setting, the police records note: “This adjustment significantly reduces the effect of discrimination across protected characteristics of race, age and sex but had a substantially detrimental effect on police efficiency”. The papers add that forces argued that “a previously useful tool returned results of questionable value”.

Broader Rollout Plans

Meanwhile, the government has launched a ten-week consultation on its plans to expand the use of facial recognition technology. Policing minister Sarah Jones has labeled the technology as the “biggest breakthrough since genetic fingerprinting”.

Expert and Oversight Concerns

The chair of a police oversight board, head of the independent scrutiny and oversight board for the police race action plan, commented: “There was very little consideration through race action plan meetings of the technology deployment even with obvious cross-over with the plan’s concerns.

“This disclosure show once again that the anti-racism commitments policing has undertaken via the race action plan are not being translated into wider practice. Independent assessments have warned that new technologies are being implemented in a context where racial disparities, weak scrutiny and poor data collection continue to exist.

“Any use of facial recognition must meet rigorous official guidelines, be independently scrutinised, and demonstrate it diminishes rather than exacerbates racial disparity.”

Official Statement

A government representative said: “We takes the conclusions of the study seriously and we have implemented changes. A new algorithm has been externally evaluated and procured, which has demonstrated no measurable discrimination. It will be trialled early next year and will be subject to further assessment.

“The foremost aim is ensuring public safety. This gamechanging technology will assist officers to apprehend and prosecute offenders. There is human involvement in each stage of the process and no further action would be taken without specialist personnel meticulously examining the results.”