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Law enforcement agencies across the UK successfully lobbied to use a face scanning system acknowledged as discriminatory against women, youths, and individuals from ethnic minority groups, following complaints that a more accurate version produced fewer investigative leads.

How the System Works

UK forces use the national police database to carry out retrospective facial recognition searches. This procedure entails matching a reference photograph of a suspect against a database of more than 19 million mugshots to identify possible hits.

Acknowledged Discrimination

The UK interior ministry admitted last week that the system was biased. This admission came after a study by the National Physical Laboratory (NPL) found it misidentified Black and Asian people and females at significantly higher rates than Caucasian males. The ministry said it “had acted on the findings”.

“It prompts the question of whether facial recognition only becomes useful if users accept biases in race and sex. Operational ease is a poor argument for overriding basic freedoms.”

Long-Standing Problem

Official papers show that this discriminatory flaw has been recognized for more than a year. Furthermore, police forces argued to overturn an earlier ruling that was designed to address the problem.

Senior officers were informed of the algorithmic discrimination in late 2024. The government-ordered NPL review found the system was more likely to produce incorrect matches for photos of women, individuals of Black ethnicity, and those under 40 years old.

A Policy U-Turn

In response, the national police leadership body mandated that the accuracy setting required for possible hits be raised to a level where the bias was significantly reduced.

However, this decision was reversed the following month after forces complained that the adjusted system was producing a lower number of “useful lines of inquiry”. Internal records show the higher threshold cut the proportion of queries resulting in possible identifications from over half to a just 14%.

Severe Disparities

Although the Home Office and NPCC refused to say what setting is currently used, the latest independent review found the system could produce false positives for women of Black heritage almost 100 times more frequently than for Caucasian women at certain settings.

The Home Office stated on these findings: “Our evaluation found 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

Describing the impact of the brief increase to the system's accuracy setting, the NPCC documents state: “This adjustment significantly reduces the impact of discrimination across protected characteristics of ethnicity, generation and gender but had a substantially detrimental effect on operational effectiveness”. The documents add that forces complained that “a once effective tactic now delivered results of questionable value”.

Broader Rollout Plans

Meanwhile, the government has launched a ten-week public review on its proposals to widen the use of biometric scanning systems. Policing minister Sarah Jones has described the technology as the “most significant advance since DNA matching”.

Criticism from Advisors and Monitors

The chair of a police oversight board, chair of the advisory panel for the national policing equality strategy, commented: “There was scant discussion through equality strategy sessions of the facial recognition rollout even with clear relevance with the plan’s concerns.

“This disclosure show once again that the pledges to combat discrimination policing has made through the race action plan are failing to be integrated into broader operations. Independent assessments have warned that innovative tools are being implemented in a landscape where ethnic inequalities, inadequate oversight and poor data collection already persist.

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

Home Office Response

A Home Office spokesperson stated: “We takes the conclusions of the report 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 trialled in the coming months and will be subject to evaluation.

“Our priority is protecting the public. This revolutionary tool will support police to put criminals and rapists behind bars. There is officer review in each stage of the procedure and no arrest or charge would be taken without specialist personnel carefully reviewing the output.”