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Law enforcement agencies across the UK successfully lobbied to deploy a face scanning system known to be discriminatory against females, young people, and individuals from minority ethnic backgrounds, after complaining that a more accurate version generated a reduced number of investigative leads.

How the System Works

British police use the police national database (PND) to conduct searches using historical face recognition. This process entails matching a reference photograph of a person of interest against a database of over 19 million custody photos to identify possible hits.

Acknowledged Discrimination

The UK interior ministry conceded last week that the technology was flawed. This admission came after a review by the National Physical Laboratory (NPL) found it incorrectly matched people of Black and Asian heritage and women at much greater frequency than Caucasian males. The Home Office said it “took steps on the findings”.

“This raises the question of whether facial recognition only becomes useful if users accept discrimination in ethnicity and gender. Convenience is a weak argument for disregarding basic freedoms.”

Known Issue

Official papers show that this bias has been recognized for more than a year. Furthermore, police forces lobbied to reverse an initial decision that was intended to address the problem.

Police bosses were notified of the algorithmic discrimination in late 2024. The Home Office-commissioned laboratory study found the system was more likely to produce incorrect matches for images depicting women, individuals of Black ethnicity, and those aged 40 and under.

A Reversed Decision

In response, the National Police Chiefs’ Council (NPCC) ordered that the accuracy setting required for potential matches be increased to a level where the bias was significantly reduced.

However, this directive was reversed the next month following complaints from police that the modified technology was generating fewer “investigative leads”. Internal records indicate the stricter setting reduced the number of queries that yielded possible identifications from over half to a just 14%.

Profound Inequalities

Although the Home Office and NPCC refused to say what setting is now in operation, the recent independent review found the system could generate false positives for Black women almost 100 times more frequently than for white women at certain settings.

The ministry commented on these results: “Our evaluation identified that in a limited set of circumstances the software is has a greater tendency to incorrectly include some demographic groups in its match reports.”

Balancing Utility and Fairness

Outlining the impact of the temporary raise to the system's confidence threshold, the police records note: “The change significantly reduces the impact of discrimination across protected characteristics of race, age and gender but had a significant negative impact on operational effectiveness”. The documents further note that police units argued that “a once effective tactic now delivered outcomes of limited benefit”.

Wider Implementation Proposals

Meanwhile, the government has launched a two-and-a-half-month consultation on its plans to expand the use of biometric scanning systems. The minister for police Sarah Jones has labeled the technology as the “most significant advance since DNA matching”.

Expert and Oversight Concerns

Abimbola Johnson, chair of the independent scrutiny and oversight board for the national policing equality strategy, said: “We observed very little discussion through race action plan meetings of the facial recognition rollout even with clear relevance with the plan’s concerns.

“This disclosure show yet again that the anti-racism commitments policing has made through the race action plan are failing to be integrated into broader operations. Independent assessments have warned that new technologies are being implemented in a landscape where racial disparities, weak scrutiny and poor data collection continue to exist.

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

Official Statement

A Home Office spokesperson said: “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 demonstrated no measurable discrimination. It will be trialled early next year 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 human involvement in every step of the procedure and no arrest or charge would be pursued without trained officers carefully reviewing the results.”