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Law enforcement agencies across the United Kingdom effectively campaigned to deploy a facial recognition system known to be biased against females, young people, and members of minority ethnic backgrounds, after complaining that a less biased version produced a reduced number of investigative leads.

How the System Works

UK forces use the national police database to carry out retrospective facial recognition searches. This process involves comparing a reference photograph of a suspect against a database of more than 19 million custody photos to identify potential matches.

Acknowledged Discrimination

The Home Office conceded last week that the technology was biased. This acknowledgment came after a study by the government's National Physical Laboratory found it misidentified people of Black and Asian heritage and women at much greater frequency than Caucasian males. The Home Office said it “had acted on the findings”.

“It prompts the issue of whether facial recognition only becomes useful if users accept biases in race and sex. Convenience is a weak argument for disregarding fundamental rights.”

Long-Standing Problem

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

Police bosses were informed of the system's bias in late 2024. The Home Office-commissioned laboratory study concluded the system was more likely to produce false positives for photos of females, individuals of Black ethnicity, and those under 40 years old.

A Policy U-Turn

In reaction, the National Police Chiefs’ Council (NPCC) mandated that the accuracy setting required for possible hits be raised to a level where the disparity was greatly diminished.

However, this decision was reversed the following month following complaints from police that the adjusted system was producing fewer “useful lines of inquiry”. NPCC documents show the higher threshold cut the number of searches resulting in possible identifications from 56% to a just under 15%.

Profound Inequalities

Although the authorities refused to say what threshold is now in operation, the recent NPL study found the system could generate incorrect matches for women of Black heritage almost 100 times more often than for Caucasian women at specific configurations.

The Home Office stated on these results: “Our evaluation identified that in a limited set of circumstances the algorithm is has a greater tendency to incorrectly include some demographic groups in its match reports.”

Operational Effectiveness vs. Bias

Outlining the impact of the brief increase to the system's confidence threshold, the police records state: “The change significantly reduces the effect of discrimination across legally safeguarded attributes of ethnicity, age and sex but had a substantially detrimental effect on operational effectiveness”. The papers add that police units argued that “a previously useful tool now delivered results of questionable value”.

Broader Rollout Plans

Meanwhile, the UK administration has launched a two-and-a-half-month consultation on its plans to expand the use of facial recognition technology. Policing minister Sarah Jones 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 national policing equality strategy, commented: “There was scant consideration through race action plan meetings of the technology deployment even with obvious cross-over with the strategy's goals.

“These revelations show once again that the anti-racism commitments the police has made through the equality initiative are failing to be integrated into wider practice. Independent assessments have cautioned that new technologies are being rolled out in a context where ethnic inequalities, inadequate oversight and poor data collection continue to exist.

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

Official Statement

A government representative said: “We treat the conclusions of the report seriously and we have implemented changes. A updated software has been independently tested and acquired, which has no statistically significant bias. It will be trialled in the coming months and will be subject to further assessment.

“The foremost aim is protecting the public. This revolutionary tool will support officers to put criminals and rapists behind bars. There is officer review in each stage of the process and no arrest or charge would be taken without trained officers carefully reviewing the output.”