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Law enforcement agencies across the United Kingdom effectively campaigned to deploy a face scanning system known to be discriminatory against women, youths, and members of ethnic minority groups, following complaints that a less biased version generated fewer investigative leads.

The Technology in Practice

British police utilize the police national database (PND) to carry out searches using historical face recognition. This procedure involves matching a “probe image” of a suspect against a repository of over 19 million mugshots to find potential matches.

Acknowledged Discrimination

The Home Office conceded last week that the system was flawed. This admission came after a review by the government's National Physical Laboratory found it incorrectly matched people of Black and Asian heritage and women at significantly higher rates than white men. The Home Office stated it “took steps on the findings”.

“It prompts the question of whether facial recognition only becomes effective if users accept discrimination in race and gender. Convenience is a weak argument for overriding fundamental rights.”

Known Issue

Official papers show that this discriminatory flaw has been recognized for more than a year. Furthermore, law enforcement lobbied to reverse an earlier ruling that was designed to address the problem.

Police bosses were informed of the algorithmic discrimination in late 2024. The Home Office-commissioned laboratory study found the system was had a higher probability to produce false positives for images depicting females, Black people, and those under 40 years old.

A Reversed Decision

In reaction, the National Police Chiefs’ Council (NPCC) mandated that the confidence threshold required for possible hits be increased to a point where the bias was significantly reduced.

However, this directive was reversed the next month following complaints from police that the modified technology was producing a lower number of “investigative leads”. Internal records show the stricter setting cut the proportion of queries that yielded possible identifications from 56% to a just 14%.

Severe Disparities

Although the Home Office and NPCC declined to specify what setting is currently used, the latest independent review found the system could generate incorrect matches for Black women almost 100 times more frequently than for Caucasian women at specific configurations.

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

Operational Effectiveness vs. Bias

Describing the effect of the temporary raise to the system's confidence threshold, the NPCC documents state: “This adjustment significantly reduces the impact of discrimination across legally safeguarded attributes of race, generation and sex but had a significant negative impact on police efficiency”. The documents further note that police units complained that “a previously useful tool returned results of limited benefit”.

Broader Rollout Plans

Meanwhile, the government has opened a two-and-a-half-month public review on its plans to expand the use of biometric scanning systems. The minister for police the relevant minister has described the technology as the “most significant advance since genetic fingerprinting”.

Criticism from Advisors and Monitors

The chair of a police oversight board, chair of the advisory panel for the police race action plan, commented: “There was very little consideration in equality strategy sessions of the technology deployment despite obvious cross-over with the plan’s concerns.

“These revelations show once again that the anti-racism commitments the police has made through the race action plan are failing to be integrated into broader operations. Independent assessments have warned that innovative tools are being implemented in a context where ethnic inequalities, weak scrutiny and faulty information gathering already persist.

“Any use of facial recognition must adhere to strict national standards, be subject to external review, and demonstrate it reduces rather than compounds ethnic bias.”

Official Statement

A government representative said: “The Home Office treat the findings of the report seriously and we have implemented changes. A new algorithm has been independently tested and acquired, which has no statistically significant bias. It will be tested early next year and will be undergo evaluation.

“Our priority is protecting the public. This revolutionary tool will assist officers to apprehend and prosecute offenders. There is officer review in each stage of the process and no arrest or charge would be pursued without specialist personnel carefully reviewing the results.”