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Law enforcement agencies across the United Kingdom successfully lobbied to deploy a facial recognition system acknowledged as discriminatory against females, young people, and members of ethnic minority groups, following complaints that a more accurate version generated a reduced number of potential suspects.

How the System Works

UK forces utilize the national police database to carry out retrospective facial recognition searches. This process involves comparing a reference photograph of a person of interest against a repository of over 19 million mugshots to identify potential matches.

Acknowledged Discrimination

The Home Office admitted last week that the technology was biased. This acknowledgment followed a study by the National Physical Laboratory (NPL) determined it incorrectly matched Black and Asian people and women at much greater frequency than Caucasian males. The ministry stated it “took steps on the findings”.

“This raises the question of whether this technology only becomes effective if users accept biases in race and gender. Convenience is a weak argument for disregarding fundamental rights.”

Known Issue

Official papers reveal that this discriminatory flaw has been recognized for over twelve months. Furthermore, police forces lobbied to reverse an earlier ruling that was designed to address the problem.

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

A Policy U-Turn

In reaction, the national police leadership body ordered that the confidence threshold required for possible hits be raised to a point where the bias was significantly reduced.

However, this directive was reversed the following month after forces complained that the modified technology was generating a lower number of “useful lines of inquiry”. Internal records indicate the stricter setting reduced the number of searches resulting in potential matches from over half to a just 14%.

Severe Disparities

Although the Home Office and NPCC declined to specify what setting is now in operation, the latest independent review discovered the system could generate false positives for women of Black heritage almost 100 times more frequently than for white women at certain settings.

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

Operational Effectiveness vs. Bias

Outlining the impact of the temporary raise to the system's accuracy setting, the NPCC documents state: “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 forces argued that “a once effective tactic returned results of questionable value”.

Wider Implementation Proposals

Meanwhile, the UK administration has launched a ten-week public review on its proposals to widen the use of facial recognition technology. Policing minister Sarah Jones has described the technology as the “biggest breakthrough since genetic fingerprinting”.

Expert and Oversight Concerns

The chair of a police oversight board, head of the independent scrutiny and oversight board for the national policing equality strategy, said: “There was very little discussion through equality strategy sessions of the facial recognition rollout even with clear relevance with the plan’s concerns.

“This disclosure demonstrate yet again that the pledges to combat discrimination the police has undertaken through the race action plan are failing to be integrated into wider practice. Independent assessments have warned that new technologies are being implemented in a context where racial disparities, weak scrutiny and poor data collection already persist.

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

Home Office Response

A Home Office spokesperson stated: “We treat the conclusions of the report 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 undergo further assessment.

“Our priority is ensuring public safety. This revolutionary tool will support police to put criminals and rapists behind bars. There is human involvement in every step of the process and no arrest or charge would be pursued without specialist personnel meticulously examining the output.”