🔗 Share this article

Law enforcement agencies across the United Kingdom effectively campaigned to deploy a facial recognition system acknowledged as biased against females, youths, and individuals from minority ethnic backgrounds, after complaining 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 procedure involves matching a “probe image” of a person of interest against a database of more than 19 million custody photos to find possible hits.

Admitted Bias

The Home Office admitted last week that the technology was flawed. This acknowledgment came after a review by the National Physical Laboratory (NPL) found it incorrectly matched people of Black and Asian heritage and women at significantly higher rates than white men. The Home Office said it “took steps on the findings”.

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

Long-Standing Problem

Internal documents show that this discriminatory flaw has been recognized for over twelve months. Furthermore, law enforcement lobbied to reverse an initial decision that was intended to address the problem.

Police bosses were informed of the algorithmic discrimination in late 2024. The Home Office-commissioned NPL review concluded the system was more likely to suggest false positives for photos of women, individuals of Black ethnicity, and those aged 40 and under.

A Reversed Decision

In reaction, the National Police Chiefs’ Council (NPCC) ordered that the accuracy setting required for potential matches be increased to a point where the bias was greatly diminished.

However, this decision was overturned the next month following complaints from police that the modified technology was generating a lower number of “investigative leads”. Internal records indicate the stricter setting reduced the number of queries that yielded potential matches from over half to a mere 14%.

Severe Disparities

Although the authorities refused to say what threshold is now in operation, the latest NPL study discovered the system could generate false positives for women of Black heritage nearly a hundred times more frequently than for Caucasian women at specific configurations.

The ministry commented on these findings: “Our evaluation identified that in a specific scenarios the algorithm is has a greater tendency to incorrectly include some demographic groups in its search results.”

Balancing Utility and Fairness

Describing the effect of the temporary raise to the system's confidence threshold, the police records state: “This adjustment greatly lessens the effect of bias across protected characteristics of race, generation 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 UK administration has launched a ten-week consultation on its proposals to widen the use of biometric scanning systems. Policing minister the relevant minister has labeled the tool as the “most significant advance since DNA matching”.

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 scant consideration in race action plan meetings of the facial recognition rollout even with obvious cross-over with the plan’s concerns.

“These revelations show once again that the anti-racism commitments the police has undertaken via the equality initiative are not being translated into wider practice. Our reports have cautioned that new technologies are being rolled out in a context where ethnic inequalities, inadequate oversight and faulty information gathering already persist.

“Any use of this technology must adhere to strict national standards, be independently scrutinised, and prove it reduces rather than exacerbates racial disparity.”

Official Statement

A government representative stated: “The Home Office takes the findings of the report seriously and we have implemented changes. A new algorithm has been independently tested and procured, which has demonstrated no measurable discrimination. It will be tested early next year and will be subject to further assessment.

“Our priority is protecting the public. This gamechanging technology will support officers to put criminals and rapists behind bars. There is officer review in every step of the procedure and no further action would be pursued without trained officers carefully reviewing the output.”