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Police forces across the United Kingdom effectively campaigned to deploy a face scanning system acknowledged as biased against women, youths, and individuals from minority ethnic backgrounds, following complaints that a less biased version generated fewer investigative leads.

The Technology in Practice

UK forces utilize the police national database (PND) to carry out searches using historical face recognition. This process involves matching a “probe image” of a suspect against a database of over 19 million mugshots to find possible hits.

Acknowledged Discrimination

The UK interior ministry conceded last week that the technology was flawed. This acknowledgment came after a study by the government's National Physical Laboratory determined it incorrectly matched people of Black and Asian heritage and women at much greater frequency than white men. The ministry said it “took steps on the findings”.

“This raises the issue of whether facial recognition only becomes effective if users accept biases in ethnicity and gender. Operational ease is a weak argument for overriding fundamental rights.”

Long-Standing Problem

Official papers reveal that this discriminatory flaw has been known about for over twelve months. Furthermore, law enforcement argued to overturn an earlier ruling that was intended to address the problem.

Police bosses were informed of the system's bias in September 2024. The government-ordered NPL review found the system was more likely to suggest incorrect matches for photos of women, Black people, and those aged 40 and under.

A Policy U-Turn

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

However, this directive was overturned the next month after forces complained that the modified technology was producing fewer “useful lines of inquiry”. NPCC documents show the stricter setting reduced the proportion of queries that yielded potential matches from over half to a just 14%.

Profound Inequalities

Although the Home Office and NPCC refused to say what threshold is now in operation, the recent NPL study found the system could generate incorrect matches for women of Black heritage nearly a hundred times more frequently than for white women at certain settings.

The Home Office stated on these results: “Our evaluation found that in a specific scenarios the algorithm is more likely to wrongly flag some demographic groups in its search results.”

Operational Effectiveness vs. Bias

Describing the impact of the brief increase to the system's accuracy setting, the police records state: “The change greatly lessens the impact of bias across legally safeguarded attributes of ethnicity, age and sex but had a significant negative impact on police efficiency”. The papers add that police units argued that “a once effective tactic now delivered results of limited benefit”.

Wider Implementation Proposals

Meanwhile, the UK administration has opened a ten-week public review on its proposals to widen the use of facial recognition technology. The minister for police the relevant minister has labeled the technology as the “most significant advance since genetic fingerprinting”.

Expert and Oversight Concerns

Abimbola Johnson, head of the independent scrutiny and oversight board for the police race action plan, commented: “There was very little consideration in race action plan meetings of the facial recognition rollout even with clear relevance with the strategy's goals.

“These revelations demonstrate once again that the anti-racism commitments the police has made via the equality initiative are failing to be integrated into wider practice. Our reports have cautioned that new technologies are being rolled out in a context where racial disparities, inadequate oversight and poor data collection continue to exist.

“Any use of facial recognition must adhere to strict national standards, be independently scrutinised, and demonstrate it diminishes rather than compounds ethnic bias.”

Home Office Response

A government representative stated: “We takes the conclusions of the study seriously and we have implemented changes. A new algorithm has been externally evaluated and acquired, which has demonstrated no measurable discrimination. It will be tested early next year and will be subject to further assessment.

“Our priority is protecting the public. This gamechanging technology will assist officers to put criminals and rapists behind bars. There is officer review in every step of the process and no arrest or charge would be taken without trained officers meticulously examining the results.”