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Law enforcement agencies across the United Kingdom effectively campaigned to deploy a face scanning system acknowledged as discriminatory against females, young people, and members of ethnic minority groups, following complaints that a more accurate version produced fewer potential suspects.

How the System Works

British police use the police national database (PND) to conduct retrospective facial recognition searches. This procedure involves matching a reference photograph of a suspect against a repository of more than 19 million mugshots to identify potential matches.

Acknowledged Discrimination

The UK interior ministry conceded last week that the system was flawed. This acknowledgment came after a study by the government's National Physical Laboratory determined it incorrectly matched Black and Asian people and women at significantly higher rates than Caucasian males. The Home Office stated it “took steps on the findings”.

“It prompts the issue of whether this technology only becomes useful if users tolerate biases in race and gender. Operational ease is a weak argument for disregarding basic freedoms.”

Known Issue

Internal documents show that this discriminatory flaw has been known about for over twelve months. Furthermore, police forces lobbied to reverse an earlier ruling that was intended to address the problem.

Police bosses were notified of the algorithmic discrimination in September 2024. The Home Office-commissioned laboratory study concluded the system was had a higher probability to suggest false positives for images depicting women, Black people, and those under 40 years old.

A Reversed Decision

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

However, this decision was reversed the next month following complaints from police that the modified technology was generating fewer “useful lines of inquiry”. NPCC documents indicate the higher threshold reduced the number of searches that yielded potential matches from over half to a just under 15%.

Severe Disparities

Although the authorities refused to say what threshold is currently used, the recent independent review found the system could produce incorrect matches for Black women nearly a hundred times more often than for Caucasian women at specific configurations.

The Home Office stated on these results: “The testing found that in a limited set of circumstances the software is more likely to incorrectly include some population segments in its search results.”

Balancing Utility and Fairness

Outlining the impact of the brief increase to the system's accuracy setting, the NPCC documents note: “The change greatly lessens the effect of discrimination across legally safeguarded attributes of ethnicity, age and gender but had a significant negative impact on police efficiency”. The documents add that police units complained that “a previously useful tool returned results of limited benefit”.

Wider Implementation Proposals

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 the relevant minister has labeled the tool as the “biggest breakthrough since genetic fingerprinting”.

Expert and Oversight Concerns

Abimbola Johnson, chair of the advisory panel for the national policing equality strategy, commented: “We observed scant discussion through equality strategy sessions of the facial recognition rollout even with clear relevance with the plan’s concerns.

“These revelations show yet again that the anti-racism commitments the police has undertaken through the race action plan are not being translated into broader operations. Our reports have warned that innovative tools are being rolled out in a context where ethnic inequalities, inadequate oversight and poor data collection already persist.

“All deployment of facial recognition must adhere to rigorous official guidelines, be independently scrutinised, and prove it diminishes rather than compounds racial disparity.”

Home Office Response

A government representative said: “We treat the findings of the study seriously and we have implemented changes. A updated software has been independently tested and acquired, which has no statistically significant bias. It will be tested early next year and will be undergo further assessment.

“The foremost aim is ensuring public safety. This revolutionary tool will assist officers to put criminals and rapists behind bars. There is human involvement in every step of the process and no further action would be taken without specialist personnel carefully reviewing the output.”