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Law enforcement agencies across the UK effectively campaigned to deploy a facial recognition system acknowledged as biased against females, youths, and members of minority ethnic backgrounds, after complaining that a more accurate version generated fewer investigative leads.

How the System Works

UK forces use the police national database (PND) to carry out searches using historical face recognition. This procedure involves comparing a reference photograph of a suspect against a repository of over 19 million mugshots to identify possible hits.

Acknowledged Discrimination

The Home Office conceded last week that the system was biased. This acknowledgment came after a study by the National Physical Laboratory (NPL) found it incorrectly matched people of Black and Asian heritage and females at significantly higher rates than Caucasian males. The Home Office said it “had acted on the findings”.

“This raises the question of whether facial recognition only becomes useful if users tolerate biases in race and gender. Operational ease is a poor argument for overriding fundamental rights.”

Long-Standing Problem

Official papers show that this discriminatory flaw has been recognized for over twelve months. Furthermore, law enforcement lobbied to reverse an earlier ruling that was designed to mitigate the problem.

Police bosses were notified of the system's bias in September 2024. The government-ordered laboratory study concluded the system was more likely to suggest incorrect matches for photos of women, individuals of Black ethnicity, and those under 40 years old.

A Reversed Decision

In reaction, the national police leadership body mandated that the accuracy setting required for potential matches be increased to a level where the bias was significantly reduced.

However, this decision was reversed the following month after forces complained that the modified technology was generating a lower number of “useful lines of inquiry”. NPCC documents indicate the higher threshold reduced the proportion of searches resulting in potential matches from 56% to a mere 14%.

Severe Disparities

Although the Home Office and NPCC declined to specify what setting is now in operation, the recent NPL study found the system could produce false positives for women of Black heritage almost 100 times more frequently than for white women at specific configurations.

The Home Office stated on these results: “Our evaluation identified that in a specific scenarios the software is more likely to wrongly flag some population segments in its match reports.”

Operational Effectiveness vs. Bias

Outlining the impact of the brief increase 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 substantially detrimental effect on police efficiency”. The papers add that forces complained that “a previously useful tool now delivered outcomes of limited benefit”.

Broader Rollout Plans

Meanwhile, the government has opened a ten-week public review on its plans to expand the use of biometric scanning systems. The minister for police Sarah Jones has described the tool as the “biggest breakthrough since genetic fingerprinting”.

Expert and Oversight Concerns

The chair of a police oversight board, chair of the advisory panel for the national policing equality strategy, commented: “There was scant consideration in 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 via the race action plan are not being translated into wider practice. Our reports have cautioned that new technologies are being rolled out in a context where ethnic inequalities, inadequate oversight and faulty information gathering already persist.

“Any use of this technology must meet rigorous official guidelines, be independently scrutinised, and demonstrate it reduces rather than exacerbates ethnic bias.”

Official Statement

A government representative said: “The Home Office treat the conclusions of the study seriously and we have implemented changes. A updated software has been externally evaluated and acquired, which has demonstrated no measurable discrimination. 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 procedure and no further action would be taken without specialist personnel carefully reviewing the output.”