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Law enforcement agencies across the UK effectively campaigned to use a face scanning system known to be discriminatory against women, youths, and individuals from ethnic minority groups, following complaints that a more accurate version produced fewer potential suspects.

How the System Works

UK forces utilize the police national database (PND) to carry out searches using historical face recognition. This process involves comparing a “probe image” of a person of interest against a repository of more than 19 million mugshots to find potential matches.

Acknowledged Discrimination

The UK interior ministry conceded last week that the technology was flawed. This acknowledgment came after a review by the government's National Physical Laboratory found it misidentified people of Black and Asian heritage and females at significantly higher rates than white men. The Home Office stated it “had acted on the findings”.

“It prompts the issue of whether facial recognition only becomes useful if users accept discrimination in race and gender. Operational ease is a poor argument for disregarding fundamental rights.”

Long-Standing Problem

Internal documents reveal that this discriminatory flaw has been known about for over twelve months. Furthermore, law enforcement argued to overturn an earlier ruling that was designed to mitigate the problem.

Senior officers were notified of the system's bias in late 2024. The government-ordered laboratory study concluded the system was had a higher probability to suggest incorrect matches for photos of females, individuals of Black ethnicity, and those under 40 years old.

A Reversed Decision

In response, the National Police Chiefs’ Council (NPCC) ordered that the confidence threshold required for potential matches be increased to a point where the bias was significantly reduced.

However, this directive was reversed the following month after forces complained that the adjusted system was generating fewer “useful lines of inquiry”. NPCC documents indicate the higher threshold cut the proportion of queries that yielded potential matches from 56% to a just under 15%.

Profound Inequalities

Although the Home Office and NPCC refused to say what setting is currently used, the recent NPL study found the system could produce incorrect matches for Black women almost 100 times more often than for Caucasian women at certain settings.

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

Balancing Utility and Fairness

Describing the impact of the temporary raise to the system's accuracy setting, the police records state: “This adjustment greatly lessens the effect of discrimination across protected characteristics of ethnicity, generation and gender but had a significant negative impact on police efficiency”. The papers further note that police units complained that “a once effective tactic returned outcomes of questionable value”.

Wider Implementation Proposals

Meanwhile, the UK administration has launched a two-and-a-half-month public review on its plans to widen the use of facial recognition technology. Policing minister the relevant minister has described the technology as the “most significant advance since genetic fingerprinting”.

Expert and Oversight Concerns

The chair of a police oversight board, chair of the independent scrutiny and oversight board for the police race action plan, commented: “We observed scant consideration in equality strategy sessions of the technology deployment despite clear relevance with the plan’s concerns.

“This disclosure show once again that the anti-racism commitments policing has made through the equality initiative are failing to be integrated into wider practice. Our reports have warned that innovative tools are being implemented in a context where racial disparities, inadequate oversight and poor data collection already persist.

“Any use of facial recognition must adhere to rigorous official guidelines, be independently scrutinised, and demonstrate it reduces rather than compounds racial disparity.”

Official Statement

A Home Office spokesperson said: “The Home Office takes the findings of the report seriously and we have implemented changes. A updated software has been externally evaluated and procured, which has demonstrated no measurable discrimination. It will be tested early next year and will be subject to further assessment.

“The foremost aim is protecting the public. This gamechanging technology will support officers to put criminals and rapists behind bars. There is human involvement in each stage of the process and no further action would be taken without specialist personnel carefully reviewing the output.”