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

How the System Works

British police utilize the national police database to conduct searches using historical face recognition. This procedure involves comparing a “probe image” of a suspect against a database of over 19 million custody photos to find potential matches.

Admitted Bias

The UK interior ministry conceded last week that the system was flawed. This admission followed a review by the government's National Physical Laboratory determined it misidentified people of Black and Asian heritage and women at significantly higher rates than white men. The ministry said it “took steps on the findings”.

“This raises the question of whether facial recognition only becomes effective if users tolerate 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 more than a year. Furthermore, law enforcement lobbied to reverse an earlier ruling that was intended to address the problem.

Senior officers were informed of the algorithmic discrimination in September 2024. The Home Office-commissioned laboratory study found the system was had a higher probability to suggest incorrect matches for photos of females, Black people, and those under 40 years old.

A Reversed Decision

In response, the National Police Chiefs’ Council (NPCC) mandated that the accuracy setting required for possible hits be raised to a point where the bias was significantly reduced.

However, this decision was overturned the next month after forces complained that the modified technology was generating fewer “investigative leads”. Internal records indicate the stricter setting cut the number of queries that yielded possible identifications 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 independent review discovered the system could produce false positives for Black women almost 100 times more frequently than for Caucasian women at specific configurations.

The Home Office stated on these findings: “Our evaluation found that in a limited set of circumstances the algorithm is has a greater tendency to incorrectly include some demographic groups in its match reports.”

Operational Effectiveness vs. Bias

Outlining the impact of the temporary raise to the system's accuracy setting, the NPCC documents note: “This adjustment significantly reduces the impact of discrimination across legally safeguarded attributes of ethnicity, age and gender but had a significant negative impact on operational effectiveness”. The papers add that police units argued that “a once effective tactic returned outcomes of limited benefit”.

Wider Implementation Proposals

Meanwhile, the government has opened a two-and-a-half-month public review on its proposals to widen the use of facial recognition technology. The minister for police the relevant minister has described the tool as the “most significant advance since genetic fingerprinting”.

Expert and Oversight Concerns

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

“These revelations show once again that the pledges to combat discrimination the police has undertaken via the race action plan are failing to be integrated into broader operations. Our reports have cautioned that innovative tools are being implemented in a context where racial disparities, inadequate oversight and faulty information gathering already persist.

“All deployment of facial recognition must meet strict national standards, be independently scrutinised, and prove it diminishes rather than compounds racial disparity.”

Official Statement

A government representative stated: “We takes the conclusions of the study seriously and we have already taken action. A new algorithm has been externally evaluated and acquired, which has no statistically significant bias. It will be trialled early next year and will be subject to further assessment.

“Our priority is ensuring public safety. This revolutionary tool will support police to apprehend and prosecute offenders. There is officer review in every step of the procedure and no further action would be taken without trained officers meticulously examining the output.”