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Law enforcement agencies across the UK effectively campaigned to deploy a facial recognition system known to be discriminatory against females, youths, and members of ethnic minority groups, following complaints that a less biased version generated fewer potential suspects.

The Technology in Practice

UK forces utilize the national police database to conduct searches using historical face recognition. This procedure involves comparing a “probe image” of a suspect against a repository of more than 19 million custody photos to identify potential matches.

Acknowledged Discrimination

The Home Office admitted last week that the system was biased. This acknowledgment came after a study by the National Physical Laboratory (NPL) found it misidentified Black and Asian people and women at significantly higher rates than white men. The Home Office stated it “took steps on the findings”.

“It prompts the question of whether facial recognition only becomes effective if users tolerate discrimination in race and gender. Convenience is a weak argument for overriding basic freedoms.”

Long-Standing Problem

Official papers show that this discriminatory flaw has been known about for over twelve months. Furthermore, police forces lobbied to reverse an earlier ruling that was designed to mitigate the problem.

Senior officers were informed of the algorithmic discrimination in September 2024. The Home Office-commissioned laboratory study found the system was more likely to produce false positives for images depicting females, Black people, and those under 40 years old.

A Policy U-Turn

In response, the National Police Chiefs’ Council (NPCC) mandated that the accuracy setting required for potential matches be raised 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 generating fewer “useful lines of inquiry”. Internal records indicate the stricter setting reduced the proportion of searches that yielded potential matches from over half to a just under 15%.

Severe Disparities

Although the authorities declined to specify what threshold is currently used, the recent independent review discovered the system could generate false positives for women of Black heritage nearly a hundred times more frequently than for white women at certain settings.

The ministry stated on these findings: “Our evaluation found that in a specific scenarios the software is has a greater tendency to wrongly flag some population segments in its match reports.”

Operational Effectiveness vs. Bias

Describing the effect of the brief increase to the system's accuracy setting, the NPCC documents state: “This adjustment significantly reduces the effect of discrimination across legally safeguarded attributes of ethnicity, generation and gender but had a significant negative impact on operational effectiveness”. The papers add that police units argued that “a previously useful tool now delivered outcomes of questionable value”.

Wider Implementation Proposals

Meanwhile, the government has opened a two-and-a-half-month public review on its plans to expand 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

Abimbola Johnson, chair of the advisory panel for the police race action plan, commented: “There was very little discussion through race action plan meetings of the facial recognition rollout despite obvious cross-over with the plan’s concerns.

“This disclosure show once again that the anti-racism commitments policing has made through the race action plan are not being translated into broader operations. Independent assessments have warned that new technologies are being rolled out in a context where racial disparities, inadequate oversight and faulty information gathering already persist.

“All deployment of this technology must meet strict national standards, be subject to external review, and prove it reduces rather than compounds racial disparity.”

Official Statement

A government representative said: “The Home Office takes the conclusions of the study with utmost gravity and we have already taken action. A updated software has been independently tested and procured, which has demonstrated no measurable discrimination. It will be tested in the coming months and will be subject to evaluation.

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