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Law enforcement agencies across the United Kingdom effectively campaigned to use a facial recognition system acknowledged as discriminatory against females, youths, and individuals from minority ethnic backgrounds, after complaining that a more accurate version generated fewer potential suspects.

How the System Works

British police use the police national database (PND) to carry out retrospective facial recognition searches. This process involves matching a “probe image” of a person of interest against a repository of more than 19 million custody photos to identify possible hits.

Admitted Bias

The UK interior ministry conceded last week that the system was flawed. This acknowledgment came after a review 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 Home Office stated it “took steps on the findings”.

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

Long-Standing Problem

Internal documents reveal that this discriminatory flaw has been recognized for more than a year. Furthermore, law enforcement argued to overturn an initial decision that was designed to address the problem.

Police bosses were informed of the system's bias in late 2024. The government-ordered laboratory study found the system was more likely to suggest 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 Chiefs’ Council (NPCC) mandated that the confidence threshold required for potential matches be increased to a level where the bias was greatly diminished.

However, this directive was overturned the next month after forces complained that the modified technology was producing a lower number of “useful lines of inquiry”. NPCC documents show the higher threshold reduced the proportion of searches that yielded potential matches from 56% to a just 14%.

Severe Disparities

Although the authorities refused to say what setting is currently used, the latest independent review discovered the system could produce false positives for Black women almost 100 times more often than for white women at certain settings.

The Home Office stated on these findings: “The testing found that in a specific scenarios the software is more likely to wrongly flag some population segments in its search results.”

Balancing Utility and Fairness

Outlining the effect of the brief increase to the system's accuracy setting, the NPCC documents state: “The change greatly lessens the effect of discrimination across legally safeguarded attributes 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 results of questionable value”.

Wider Implementation Proposals

Meanwhile, the UK administration has launched a ten-week consultation on its plans to expand the use of facial recognition technology. Policing minister the relevant minister has described the technology as the “most significant advance since DNA matching”.

Expert and Oversight Concerns

The chair of a police oversight board, chair of the independent scrutiny and oversight board for the police race action plan, commented: “We observed very little discussion in equality strategy sessions of the technology deployment despite obvious cross-over with the strategy's goals.

“This disclosure demonstrate yet again that the anti-racism commitments policing has undertaken through the race action plan are failing to be integrated into broader operations. Independent assessments have cautioned that innovative tools are being implemented in a landscape where racial disparities, inadequate oversight and poor data collection already persist.

“All deployment of facial recognition must adhere to rigorous official guidelines, be subject to external review, and demonstrate it diminishes rather than exacerbates ethnic bias.”

Home Office Response

A government representative stated: “The Home Office takes the conclusions of the report seriously and we have implemented changes. A new algorithm has been independently tested and acquired, which has demonstrated no measurable discrimination. It will be tested early next year and will be undergo further assessment.

“Our priority is protecting the public. This gamechanging technology will assist officers to put criminals and rapists behind bars. There is officer review in each stage of the process and no further action would be taken without specialist personnel carefully reviewing the results.”