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Law enforcement agencies across the United Kingdom successfully lobbied to deploy a facial recognition system known to be discriminatory against women, young people, and individuals from minority ethnic backgrounds, after complaining that a more accurate version produced fewer potential suspects.

The Technology in Practice

UK forces use the police national database (PND) to conduct retrospective facial recognition searches. This process involves comparing a “probe image” of a suspect against a database of over 19 million mugshots to identify potential matches.

Admitted Bias

The Home Office admitted last week that the technology was flawed. This acknowledgment came after a review by the government's National Physical Laboratory determined it misidentified people of Black and Asian heritage and females at significantly higher rates than white men. The Home Office stated it “took steps on the findings”.

“This raises the question of whether facial recognition only becomes effective if users accept biases in ethnicity and sex. Operational ease is a weak argument for overriding fundamental rights.”

Long-Standing Problem

Internal documents reveal that this discriminatory flaw has been recognized for more than a year. Furthermore, police forces lobbied to reverse an earlier ruling that was designed to mitigate the problem.

Senior officers were notified of the system's bias in September 2024. The government-ordered NPL review found the system was had a higher probability to suggest false positives for images depicting females, Black people, and those aged 40 and under.

A Policy U-Turn

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

However, this directive was overturned the following month after forces complained that the adjusted system was producing fewer “useful lines of inquiry”. Internal records indicate the higher threshold reduced the number of searches that yielded potential matches from over half to a mere under 15%.

Profound Inequalities

Although the Home Office and NPCC refused to say what threshold is currently used, the recent NPL study discovered the system could generate incorrect matches for women of Black heritage almost 100 times more frequently than for Caucasian women at certain settings.

The ministry commented on these findings: “The testing identified that in a specific scenarios the software is more likely to incorrectly include some demographic groups in its match reports.”

Operational Effectiveness vs. Bias

Outlining the effect of the brief increase to the system's confidence threshold, the NPCC documents state: “This adjustment greatly lessens the effect of discrimination across protected characteristics of race, generation and sex but had a substantially detrimental effect on operational effectiveness”. The papers add that police units argued that “a previously useful tool now delivered results of limited benefit”.

Wider Implementation Proposals

Meanwhile, the UK administration has launched a ten-week consultation on its proposals to expand the use of facial recognition technology. The minister for police Sarah Jones has labeled the technology as the “most significant advance since genetic fingerprinting”.

Expert and Oversight Concerns

Abimbola Johnson, head of the independent scrutiny and oversight board for the national policing equality strategy, said: “We observed scant consideration in equality strategy sessions of the facial recognition rollout despite clear relevance with the plan’s concerns.

“These revelations demonstrate once again that the anti-racism commitments the police has made through the equality initiative are failing to be integrated into wider practice. Independent assessments have cautioned that innovative tools are being rolled out in a context where ethnic inequalities, weak scrutiny and faulty information gathering already persist.

“All deployment of facial recognition must meet rigorous official guidelines, be subject to external review, and prove it reduces rather than compounds racial disparity.”

Official Statement

A Home Office spokesperson stated: “The Home Office takes the conclusions of the study with utmost gravity and we have implemented changes. A new algorithm has been externally evaluated and procured, which has demonstrated no measurable discrimination. It will be trialled in the coming months and will be undergo evaluation.

“The foremost aim is ensuring public safety. This revolutionary tool will support officers to apprehend and prosecute offenders. There is officer review in each stage of the process and no further action would be pursued without trained officers meticulously examining the results.”