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Law enforcement agencies across the United Kingdom successfully lobbied to use a facial recognition system acknowledged as discriminatory against females, youths, and members of minority ethnic backgrounds, following complaints that a less biased version generated fewer potential suspects.

How the System Works

UK forces utilize 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 over 19 million mugshots to find possible hits.

Admitted Bias

The Home Office admitted last week that the system was flawed. This admission followed a study by the National Physical Laboratory (NPL) determined it incorrectly matched Black and Asian people and women at much greater frequency than Caucasian males. The ministry stated it “had acted on the findings”.

“It prompts the issue of whether this technology only becomes effective if users tolerate biases in race and sex. Operational ease is a poor argument for disregarding basic freedoms.”

Known Issue

Official papers show that this bias has been recognized for more than a year. Furthermore, law enforcement lobbied to reverse an earlier ruling that was designed to mitigate the problem.

Police bosses were notified of the system's bias in September 2024. The government-ordered NPL review concluded the system was had a higher probability to produce false positives for photos of women, individuals of Black ethnicity, and those under 40 years old.

A Policy U-Turn

In reaction, the National Police Chiefs’ Council (NPCC) ordered that the accuracy setting required for possible hits be increased to a point where the bias was significantly reduced.

However, this directive was overturned the next month after forces complained that the modified technology was generating fewer “useful lines of inquiry”. NPCC documents indicate the higher threshold cut the number of queries resulting in possible identifications from over half to a mere 14%.

Severe Disparities

Although the Home Office and NPCC refused to say what threshold is currently used, the latest independent review discovered the system could produce incorrect matches for Black women almost 100 times more frequently than for white women at certain settings.

The Home Office commented on these results: “Our evaluation found that in a limited set of circumstances the software is has a greater tendency to wrongly flag some population segments in its search results.”

Balancing Utility and Fairness

Describing the effect of the brief increase to the system's confidence threshold, the police records state: “This adjustment 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 add that police units complained that “a previously useful tool now delivered outcomes of limited benefit”.

Broader Rollout Plans

Meanwhile, the UK administration has launched a two-and-a-half-month consultation on its plans to expand the use of biometric scanning systems. The minister for police Sarah Jones has labeled the tool as the “most significant advance since DNA matching”.

Criticism from Advisors and Monitors

The chair of a police oversight board, chair of the advisory panel for the police race action plan, said: “There was very little consideration through race action plan meetings of the technology deployment despite obvious cross-over with the strategy's goals.

“This disclosure show once again that the anti-racism commitments policing has undertaken via the race action plan are failing to be integrated into broader operations. Our reports have cautioned that new technologies are being rolled out in a landscape where racial disparities, weak scrutiny and poor data collection continue to exist.

“Any use of this technology must adhere to rigorous official guidelines, be independently scrutinised, and prove it reduces rather than exacerbates ethnic bias.”

Official Statement

A Home Office spokesperson said: “The Home Office takes the findings of the study with utmost gravity and we have implemented changes. A updated software has been independently tested and acquired, which has demonstrated no measurable discrimination. It will be trialled early next year and will be undergo evaluation.

“Our priority is ensuring public safety. This revolutionary tool will assist officers to apprehend and prosecute offenders. There is human involvement in each stage of the procedure and no arrest or charge would be taken without trained officers carefully reviewing the results.”