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Law enforcement agencies across the United Kingdom successfully lobbied to deploy a facial recognition system known to be biased against females, youths, and individuals from ethnic minority groups, following complaints that a less biased version generated fewer potential suspects.

The Technology in Practice

UK forces use the national police database to conduct searches using historical face recognition. This process involves matching a reference photograph of a suspect against a database of more than 19 million mugshots to find possible hits.

Acknowledged Discrimination

The Home Office admitted last week that the system was flawed. This admission followed a review by the government's National Physical Laboratory found it incorrectly matched Black and Asian people and females at significantly higher rates than Caucasian males. The Home Office stated it “took steps on the findings”.

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

Known Issue

Official papers reveal that this bias has been known about for over twelve months. Furthermore, law enforcement lobbied to reverse an earlier ruling that was designed to address the problem.

Police bosses were notified of the algorithmic discrimination in September 2024. The government-ordered laboratory study found the system was more likely to produce false positives for images depicting females, individuals of Black ethnicity, and those aged 40 and under.

A Reversed Decision

In response, the National Police Chiefs’ Council (NPCC) mandated that the accuracy setting required for potential matches be raised to a level where the disparity was greatly diminished.

However, this directive was overturned the following month after forces complained that the modified technology was generating fewer “investigative leads”. NPCC documents show the higher threshold reduced the number of searches resulting in possible identifications from over half to a just 14%.

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 women of Black heritage nearly a hundred times more often than for Caucasian women at specific configurations.

The ministry commented on these findings: “Our evaluation identified that in a limited set of circumstances the algorithm is has a greater tendency to incorrectly include some population segments in its search results.”

Balancing Utility and Fairness

Describing the effect of the brief increase to the system's confidence threshold, the NPCC documents note: “This adjustment greatly lessens the impact of discrimination across legally safeguarded attributes of ethnicity, generation and gender but had a substantially detrimental effect on police efficiency”. The documents add that forces argued that “a once effective tactic now delivered results of questionable value”.

Broader Rollout Plans

Meanwhile, the UK administration has opened a ten-week public review on its proposals to widen the use of biometric scanning systems. Policing minister the relevant minister has labeled the technology as the “biggest breakthrough since DNA matching”.

Criticism from Advisors and Monitors

Abimbola Johnson, chair of the independent scrutiny and oversight board for the national policing equality strategy, commented: “There was scant consideration through race action plan meetings of the facial recognition rollout even with obvious cross-over with the strategy's goals.

“This disclosure show once again that the anti-racism commitments policing has undertaken through the equality initiative are failing to be integrated into broader operations. Independent assessments have cautioned that innovative tools are being rolled out in a context where racial disparities, weak scrutiny and faulty information gathering continue to exist.

“All deployment of this technology must meet rigorous official guidelines, be independently scrutinised, and prove it diminishes rather than exacerbates racial disparity.”

Official Statement

A Home Office spokesperson said: “The Home Office treat the conclusions of the report with utmost gravity and we have already taken action. A updated software has been independently tested and acquired, which has no statistically significant bias. It will be tested in the coming months and will be subject to further assessment.

“The foremost aim is protecting the public. This revolutionary tool will support police to apprehend and prosecute offenders. There is officer review in every step of the procedure and no arrest or charge would be pursued without trained officers meticulously examining the results.”