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Police forces across the UK effectively campaigned to deploy a face scanning system acknowledged as biased against females, young people, and individuals from minority ethnic backgrounds, after complaining that a less biased version generated a reduced number of potential suspects.

The Technology in Practice

UK forces use the national police database to conduct retrospective facial recognition searches. This procedure involves comparing a reference photograph of a suspect 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 government's National Physical Laboratory determined it misidentified people of Black and Asian heritage and females at significantly higher rates than Caucasian males. 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 ethnicity and sex. Operational ease is a weak argument for overriding fundamental rights.”

Long-Standing Problem

Official papers show that this bias has been recognized for more than a year. Furthermore, law enforcement argued to overturn an initial decision that was intended to mitigate the problem.

Police bosses were informed of the algorithmic discrimination in late 2024. The government-ordered NPL review found the system was more likely to suggest false positives for images depicting females, individuals of Black ethnicity, and those under 40 years old.

A Policy U-Turn

In reaction, the national police leadership body mandated that the accuracy setting required for possible hits be raised to a level where the disparity was greatly diminished.

However, this decision was overturned the following month following complaints from police that the adjusted system was generating a lower number of “useful lines of inquiry”. NPCC documents show the stricter setting reduced the number of searches that yielded possible identifications from 56% to a mere 14%.

Severe Disparities

Although the authorities declined to specify what threshold is currently used, the recent NPL study discovered the system could generate false positives for Black women nearly a hundred times more frequently than for white women at specific configurations.

The Home Office stated on these results: “Our evaluation found that in a specific scenarios the software is more likely to wrongly flag some demographic groups in its match reports.”

Balancing Utility and Fairness

Describing the impact of the brief increase to the system's confidence threshold, the police records note: “This adjustment greatly lessens the impact of bias across protected characteristics of race, generation and sex but had a significant negative impact on operational effectiveness”. The papers further note that police units argued that “a previously useful tool returned results of limited benefit”.

Broader Rollout Plans

Meanwhile, the UK administration has opened 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”.

Criticism from Advisors and Monitors

The chair of a police oversight board, chair of the advisory panel for the police race action plan, commented: “We observed scant discussion through race action plan meetings of the facial recognition rollout even with clear relevance with the strategy's goals.

“These revelations demonstrate yet again that the anti-racism commitments the police has undertaken via the race action plan are not being translated into broader operations. Independent assessments have cautioned that innovative tools are being rolled out in a landscape where racial disparities, inadequate oversight and faulty information gathering continue to exist.

“All deployment of facial recognition must adhere to strict national standards, be subject to external review, and demonstrate it reduces rather than compounds ethnic bias.”

Official Statement

A Home Office spokesperson stated: “We treat the conclusions of the study seriously 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 in the coming months and will be subject to further assessment.

“The foremost aim 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 further action would be taken without specialist personnel meticulously examining the results.”