British Law Enforcement Agencies Lobbied to Use Discriminatory Facial Recognition Technology

Law enforcement agencies across the UK successfully lobbied to use a facial recognition system acknowledged as discriminatory against females, young people, and members of ethnic minority groups, following complaints that a more accurate version generated fewer investigative leads.

How the System Works

UK forces use the police national database (PND) to conduct searches using historical face recognition. This process entails comparing a “probe image” of a person of interest against a database of over 19 million custody photos to find potential matches.

Admitted Bias

The Home Office admitted last week that the system was flawed. This acknowledgment came after a review by the government's National Physical Laboratory determined it incorrectly matched people of Black and Asian heritage and women at significantly higher rates than Caucasian males. The Home Office said it “had acted on the findings”.

“It prompts the question of whether this technology only becomes effective if users tolerate discrimination in ethnicity and gender. Convenience is a weak argument for overriding basic freedoms.”

Long-Standing Problem

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

Police bosses were informed of the algorithmic discrimination in late 2024. The government-ordered laboratory study found the system was had a higher probability to produce incorrect matches for images depicting females, individuals of Black ethnicity, and those aged 40 and under.

A Policy U-Turn

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

However, this directive was reversed the following month following complaints from police that the adjusted system was generating fewer “investigative leads”. Internal records show the stricter setting reduced the proportion of queries that yielded possible identifications from over half to a mere 14%.

Severe Disparities

Although the Home Office and NPCC refused to say what threshold is now in operation, the latest independent review found the system could generate incorrect matches for women of Black heritage almost 100 times more often than for Caucasian women at specific configurations.

The ministry commented on these findings: “Our evaluation identified that in a limited set of circumstances the algorithm is has a greater tendency to incorrectly include some population segments in its search results.”

Balancing Utility and Fairness

Outlining the effect of the temporary raise to the system's accuracy setting, the police records state: “This adjustment significantly reduces the impact of bias across legally safeguarded attributes of race, generation and gender but had a substantially detrimental effect on police efficiency”. 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 ten-week public review on its proposals to expand the use of biometric scanning systems. The minister for police Sarah Jones has described the technology as the “most significant advance since genetic fingerprinting”.

Expert and Oversight Concerns

The chair of a police oversight board, chair of the advisory panel for the national policing equality strategy, said: “We observed scant consideration in race action plan meetings of the technology deployment despite obvious cross-over with the strategy's goals.

“These revelations show once again that the anti-racism commitments the police has undertaken via the race action plan are not being translated into broader operations. Independent assessments have warned that new technologies are being rolled out in a landscape where racial disparities, inadequate oversight and faulty information gathering already persist.

“Any use of facial recognition must meet rigorous official guidelines, be independently scrutinised, and prove it diminishes rather than exacerbates ethnic bias.”

Official Statement

A Home Office spokesperson said: “We treat the conclusions of the report seriously and we have implemented changes. A updated software has been externally evaluated and acquired, which has no statistically significant bias. It will be tested early next year and will be subject to further assessment.

“The foremost aim is ensuring public safety. This revolutionary tool will assist police to apprehend and prosecute offenders. There is officer review in each stage of the procedure and no further action would be pursued without specialist personnel carefully reviewing the results.”