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Law enforcement agencies across the UK effectively campaigned to deploy a facial recognition system acknowledged as discriminatory against women, young people, and members of minority ethnic backgrounds, following complaints that a less biased version generated a reduced number of potential suspects.

How the System Works

UK forces utilize the national police database to conduct retrospective facial recognition searches. This procedure involves comparing a “probe image” of a person of interest against a database of more than 19 million custody photos to identify possible hits.

Admitted Bias

The Home Office conceded last week that the system was biased. This admission followed a study by the government's National Physical Laboratory determined it misidentified people of Black and Asian heritage and women at much greater frequency than white men. The Home Office stated it “had acted on the findings”.

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

Long-Standing Problem

Official papers show that this discriminatory flaw has been recognized for over twelve months. Furthermore, law enforcement argued to overturn an earlier ruling that was designed to mitigate the problem.

Senior officers were informed of the system's bias in September 2024. The government-ordered NPL review concluded the system was more likely to produce false positives for photos of women, individuals of Black ethnicity, and those aged 40 and under.

A Policy U-Turn

In reaction, the National Police Chiefs’ Council (NPCC) mandated that the confidence threshold required for possible hits be increased to a point where the bias was greatly diminished.

However, this directive was overturned the next month following complaints from police that the modified technology was producing a lower number of “investigative leads”. NPCC documents show the stricter setting reduced the number of queries resulting in possible identifications from 56% to a mere under 15%.

Severe Disparities

Although the Home Office and NPCC declined to specify what setting is currently used, the recent NPL study found the system could produce false positives for women of Black heritage 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 limited set of circumstances the software is more likely to wrongly flag some demographic groups in its search results.”

Operational Effectiveness vs. Bias

Describing the impact of the temporary raise to the system's accuracy setting, the NPCC documents state: “This adjustment significantly reduces the effect of discrimination across legally safeguarded attributes of ethnicity, age and gender but had a substantially detrimental effect on police efficiency”. The papers add that police units argued that “a once effective tactic returned outcomes of questionable value”.

Broader Rollout Plans

Meanwhile, the UK administration has launched a ten-week public review on its plans to widen the use of biometric scanning systems. Policing minister the relevant minister has described the tool as the “biggest breakthrough since genetic fingerprinting”.

Criticism from Advisors and Monitors

The chair of a police oversight board, head of the independent scrutiny and oversight board for the police race action plan, said: “There was very little consideration in race action plan meetings of the facial recognition rollout despite obvious cross-over with the strategy's goals.

“These revelations show once again that the pledges to combat discrimination policing has made through the equality initiative are not being translated into wider practice. Independent assessments have warned that new technologies are being implemented in a landscape where ethnic inequalities, inadequate oversight and faulty information gathering already persist.

“All deployment of this technology must meet strict national standards, be independently scrutinised, and demonstrate it diminishes rather than compounds racial disparity.”

Home Office Response

A government representative said: “We treat the findings of the study with utmost gravity and we have implemented changes. A updated software has been externally evaluated and procured, which has demonstrated no measurable discrimination. It will be trialled in the coming months and will be undergo further assessment.

“Our priority is protecting the public. 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 further action would be pursued without trained officers carefully reviewing the results.”