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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, youths, and members of ethnic minority groups, after complaining that a less biased version generated a reduced number of potential suspects.

The Technology in Practice

UK forces utilize the police national database (PND) to conduct searches using historical face recognition. This process entails matching a “probe image” of a suspect against a repository of more than 19 million mugshots to identify potential matches.

Acknowledged Discrimination

The UK interior ministry admitted last week that the technology was biased. This admission came after a study by the government's National Physical Laboratory determined it incorrectly matched Black and Asian people and women at significantly higher rates than Caucasian males. The ministry said it “had acted on the findings”.

“It prompts the question of whether facial recognition only becomes effective if users accept discrimination in race and gender. Operational ease is a weak argument for disregarding fundamental rights.”

Known Issue

Internal documents reveal that this bias has been known about for more than a year. Furthermore, law enforcement lobbied to reverse an initial decision that was intended to mitigate the problem.

Senior officers were notified of the system's bias in late 2024. The Home Office-commissioned laboratory study found the system was more likely to produce false positives for images depicting females, individuals of Black ethnicity, and those aged 40 and under.

A Reversed Decision

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

However, this decision was overturned the next month following complaints from police that the adjusted system was generating a lower number of “useful lines of inquiry”. Internal records indicate the stricter setting reduced the number of searches resulting in possible identifications from over half to a mere under 15%.

Profound Inequalities

Although the authorities refused to say what setting is now in operation, the latest NPL study discovered the system could produce false positives for Black women almost 100 times more often than for white women at specific configurations.

The ministry commented on these results: “Our evaluation identified that in a limited set of circumstances the algorithm is more likely to incorrectly include some demographic groups in its search results.”

Balancing Utility and Fairness

Describing the effect of the temporary raise to the system's accuracy setting, the police records state: “This adjustment significantly reduces the impact of bias across legally safeguarded attributes of race, age and sex but had a significant negative impact on operational effectiveness”. The papers add that police units complained that “a once effective tactic returned results of questionable value”.

Wider Implementation Proposals

Meanwhile, the government has launched a two-and-a-half-month consultation on its plans to expand the use of facial recognition technology. The minister for police Sarah Jones has labeled the tool 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 consideration in race action plan meetings of the technology deployment despite obvious cross-over with the plan’s concerns.

“These revelations show yet again that the anti-racism commitments the police has made via the equality initiative are failing to be integrated into wider practice. Independent assessments have cautioned that new technologies are being rolled out in a landscape where ethnic inequalities, inadequate oversight and poor data collection already persist.

“All deployment of facial recognition must adhere to rigorous official guidelines, be independently scrutinised, and prove it diminishes rather than exacerbates ethnic bias.”

Official Statement

A government representative stated: “We treat the findings of the report with utmost gravity and we have already taken action. A new algorithm has been externally evaluated and procured, which has demonstrated no measurable discrimination. It will be tested in the coming months and will be subject to evaluation.

“The foremost aim is protecting the public. This gamechanging technology will support officers to put criminals and rapists behind bars. There is human involvement in every step of the process and no further action would be taken without trained officers meticulously examining the output.”