🔗 Share this article

Law enforcement agencies across the United Kingdom effectively campaigned to deploy a face scanning system known to be discriminatory against females, young people, and members of minority ethnic backgrounds, following complaints that a more accurate version produced a reduced number of investigative leads.

How the System Works

British police utilize the national police database to conduct retrospective facial recognition searches. This process entails matching a reference photograph of a person of interest against a repository of over 19 million custody photos to find possible hits.

Admitted Bias

The UK interior ministry admitted last week that the system was biased. This acknowledgment came after a study by the National Physical Laboratory (NPL) determined it misidentified Black and Asian people and females at significantly higher rates than white men. The Home Office stated it “had acted on the findings”.

“This raises the issue of whether facial recognition only becomes effective if users tolerate discrimination in race and gender. Convenience is a poor argument for disregarding fundamental rights.”

Known Issue

Official papers reveal that this discriminatory flaw has been recognized for over twelve months. Furthermore, law enforcement argued to overturn 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 NPL review concluded the system was more likely to produce false positives for images depicting women, individuals of Black ethnicity, and those under 40 years old.

A Policy U-Turn

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

However, this decision was reversed the next month following complaints from police that the adjusted system was producing a lower number of “investigative leads”. Internal records show the stricter setting cut the number of searches that yielded potential matches from 56% to a mere 14%.

Severe Disparities

Although the Home Office and NPCC declined to specify what threshold is currently used, the latest independent review discovered the system could produce incorrect matches for women of Black heritage almost 100 times more frequently than for Caucasian women at certain settings.

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

Balancing Utility and Fairness

Describing the impact of the temporary raise to the system's accuracy setting, the NPCC documents note: “This adjustment greatly lessens the impact of bias across protected characteristics of race, age and sex but had a significant negative impact on operational effectiveness”. The papers further note that police units complained that “a previously useful tool returned outcomes of questionable value”.

Wider Implementation Proposals

Meanwhile, the UK administration has launched a two-and-a-half-month consultation on its proposals to expand the use of biometric scanning systems. The minister for police Sarah Jones has described the tool as the “biggest breakthrough since DNA matching”.

Expert and Oversight Concerns

Abimbola Johnson, chair of the advisory panel for the police race action plan, commented: “We observed very little consideration through race action plan meetings of the facial recognition rollout despite clear relevance with the strategy's goals.

“This disclosure show yet again that the pledges to combat discrimination policing has undertaken through the equality initiative are not being translated into broader operations. Independent assessments have cautioned that new technologies are being implemented in a context where ethnic inequalities, weak scrutiny and poor data collection already persist.

“All deployment of this technology must meet strict national standards, be subject to external review, and demonstrate it diminishes rather than compounds ethnic bias.”

Home Office Response

A government representative stated: “The Home Office treat the findings of the report with utmost gravity and we have already taken action. A new algorithm has been independently tested and acquired, which has demonstrated no measurable discrimination. It will be trialled in the coming months and will be subject to evaluation.

“Our priority is ensuring public safety. This revolutionary tool will assist police to apprehend and prosecute offenders. There is human involvement in each stage of the process and no further action would be pursued without trained officers carefully reviewing the results.”