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Law enforcement agencies across the United Kingdom effectively campaigned to deploy a face scanning system acknowledged as discriminatory against women, youths, and members of minority ethnic backgrounds, after complaining that a less biased version generated fewer investigative leads.

How the System Works

UK forces use the police national database (PND) to carry out retrospective facial recognition searches. This procedure involves comparing a reference photograph of a suspect against a repository of more than 19 million custody photos to identify possible hits.

Admitted Bias

The Home Office admitted last week that the system was flawed. This admission followed a review by the government's National Physical Laboratory found it misidentified Black and Asian people and women at significantly higher rates than Caucasian males. The Home Office stated it “took steps on the findings”.

“This raises the question of whether facial recognition only becomes effective if users accept biases in race and sex. Convenience is a weak argument for disregarding fundamental rights.”

Long-Standing Problem

Internal documents show that this bias has been known about for over twelve months. Furthermore, police forces lobbied to reverse an earlier ruling that was designed to mitigate the problem.

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

A Reversed Decision

In response, the national police leadership body ordered that the accuracy setting required for potential matches be raised to a level where the bias was greatly diminished.

However, this decision was reversed the next month following complaints from police that the modified technology was generating fewer “useful lines of inquiry”. Internal records show the stricter setting cut the proportion of queries that yielded possible identifications from over half to a just under 15%.

Severe Disparities

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

The ministry commented on these findings: “The testing found that in a limited set of circumstances the algorithm is more likely to wrongly flag some population segments in its match reports.”

Operational Effectiveness vs. Bias

Outlining the impact of the temporary raise to the system's confidence threshold, the NPCC documents note: “This adjustment significantly reduces the effect of bias across protected characteristics of race, generation and sex but had a substantially detrimental effect on operational effectiveness”. The documents further note that police units argued that “a once effective tactic returned outcomes of limited benefit”.

Broader Rollout Plans

Meanwhile, the UK administration has launched a ten-week public review on its plans to expand the use of facial recognition technology. The minister for police Sarah Jones has described the tool as the “most significant advance since DNA matching”.

Expert and Oversight Concerns

The chair of a police oversight board, head of the independent scrutiny and oversight board for the national policing equality strategy, commented: “We observed very little consideration in race action plan meetings of the facial recognition rollout even with clear relevance with the plan’s concerns.

“This disclosure demonstrate yet again that the pledges to combat discrimination the police has made through the equality initiative are failing to be integrated into wider practice. Our reports have warned that innovative tools are being rolled out in a context where racial disparities, weak scrutiny and faulty information gathering already persist.

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

Official Statement

A Home Office spokesperson said: “We treat the findings of the report with utmost gravity and we have already taken action. A updated software has been externally evaluated and procured, which has no statistically significant bias. It will be trialled early next year and will be undergo evaluation.

“The foremost aim is ensuring public safety. This revolutionary tool will support police to put criminals and rapists behind bars. There is officer review in every step of the process and no arrest or charge would be pursued without trained officers carefully reviewing the output.”