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

How the System Works

UK forces utilize the police national database (PND) to conduct searches using historical face recognition. This procedure involves comparing a reference photograph of a person of interest against a database of more than 19 million mugshots to identify possible hits.

Acknowledged Discrimination

The Home Office conceded last week that the technology was flawed. This admission followed a review by the National Physical Laboratory (NPL) found it incorrectly matched Black and Asian people and females at significantly higher rates than white men. The ministry stated it “had acted on the findings”.

“This raises the issue of whether this technology only becomes useful if users tolerate biases in ethnicity and gender. Convenience is a weak argument for disregarding fundamental rights.”

Long-Standing Problem

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

Police bosses were informed of the system's bias in late 2024. The government-ordered NPL review found the system was had a higher probability to produce false positives for photos of females, Black people, and those under 40 years old.

A Reversed Decision

In reaction, the National Police Chiefs’ Council (NPCC) ordered that the confidence threshold required for potential matches be increased to a level where the disparity was greatly diminished.

However, this decision was overturned the following month after forces complained that the adjusted system was generating fewer “useful lines of inquiry”. Internal records show the stricter setting reduced the number of queries resulting in potential matches from over half to a just under 15%.

Severe Disparities

Although the Home Office and NPCC declined to specify what threshold is now in operation, the recent NPL study 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 commented on these results: “The testing identified that in a limited set of circumstances the algorithm is more likely to wrongly flag some demographic groups in its search results.”

Balancing Utility and Fairness

Outlining the impact of the brief increase to the system's accuracy setting, the NPCC documents note: “The change greatly lessens the effect of discrimination 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 outcomes of limited benefit”.

Wider Implementation Proposals

Meanwhile, the UK administration has launched a ten-week consultation on its proposals to widen the use of facial recognition technology. The minister for police Sarah Jones has labeled the tool as the “most significant advance since genetic fingerprinting”.

Expert and Oversight Concerns

Abimbola Johnson, head of the independent scrutiny and oversight board for the police race action plan, said: “We observed scant consideration through equality strategy sessions of the facial recognition rollout even with obvious cross-over with the plan’s concerns.

“This disclosure demonstrate yet again that the anti-racism commitments the police has made through the race action plan are not being translated into wider practice. Our reports have warned that innovative tools are being implemented in a landscape where racial disparities, weak scrutiny and faulty information gathering already persist.

“Any use of this technology must meet strict national standards, be subject to external review, and demonstrate it reduces rather than compounds ethnic bias.”

Home Office Response

A government representative said: “The Home Office takes the findings of the report with utmost gravity and we have already taken action. A new algorithm has been independently tested and procured, which has no statistically significant bias. It will be tested early next year and will be undergo further assessment.

“Our priority is protecting the public. This revolutionary tool will assist officers to apprehend and prosecute offenders. There is officer review in every step of the procedure and no arrest or charge would be pursued without trained officers carefully reviewing the output.”