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Law enforcement agencies across the United Kingdom successfully lobbied to use a face scanning system acknowledged as biased against women, young people, and individuals from ethnic minority groups, following complaints that a less biased version produced fewer investigative leads.

The Technology in Practice

UK forces use the national police database to conduct retrospective facial recognition searches. This procedure involves comparing a “probe image” of a suspect against a repository of over 19 million custody photos to find potential matches.

Acknowledged Discrimination

The UK interior ministry conceded last week that the system was flawed. This admission followed a study by the National Physical Laboratory (NPL) determined it misidentified Black and Asian people and females at significantly higher rates than white men. The Home Office stated it “took steps on the findings”.

“It prompts the issue of whether facial recognition only becomes useful if users accept discrimination in race and gender. Convenience is a poor argument for overriding fundamental rights.”

Long-Standing Problem

Internal documents show that this bias has been known about for over twelve months. Furthermore, law enforcement lobbied to reverse an initial decision that was intended to mitigate the problem.

Police bosses were informed of the algorithmic discrimination in late 2024. The government-ordered laboratory study found the system was had a higher probability to suggest false positives for photos of females, individuals of Black ethnicity, and those aged 40 and under.

A Reversed Decision

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

However, this directive was reversed the next month following complaints from police that the modified technology was producing a lower number of “useful lines of inquiry”. Internal records indicate 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 declined to specify what setting is now in operation, the latest independent review discovered the system could generate false positives for Black women nearly a hundred times more frequently than for white women at specific configurations.

The ministry stated on these results: “Our evaluation found that in a limited set of circumstances the algorithm is more likely to wrongly flag some demographic groups in its match reports.”

Balancing Utility and Fairness

Outlining the impact of the temporary raise to the system's confidence threshold, the NPCC documents state: “The change greatly lessens the impact of bias across protected characteristics of race, generation and sex but had a substantially detrimental effect on police efficiency”. The papers add that forces complained that “a once effective tactic returned outcomes of questionable value”.

Wider Implementation Proposals

Meanwhile, the UK administration has launched a two-and-a-half-month public review on its plans to widen the use of biometric scanning systems. Policing minister the relevant minister has described the technology as the “most significant advance since genetic fingerprinting”.

Criticism from Advisors and Monitors

Abimbola Johnson, chair of the independent scrutiny and oversight board for the national policing equality strategy, commented: “There was scant discussion through race action plan meetings of the facial recognition rollout despite obvious cross-over with the strategy's goals.

“These revelations show yet again that the anti-racism commitments the police has undertaken through the race action plan are failing to be integrated into broader operations. Independent assessments have warned 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 facial recognition must adhere to strict national standards, be independently scrutinised, and prove it diminishes rather than compounds ethnic bias.”

Official Statement

A Home Office spokesperson stated: “We treat the conclusions of the report seriously and we have implemented changes. A updated software 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 ensuring public safety. This revolutionary tool will assist officers to put criminals and rapists behind bars. There is officer review in each stage of the procedure and no further action would be pursued without specialist personnel carefully reviewing the results.”