British Law Enforcement Agencies Lobbied to Use Biased Facial Recognition Technology

Police forces across the UK effectively campaigned to deploy a facial recognition system known to be discriminatory against women, youths, and members of minority ethnic backgrounds, after complaining that a less biased version produced a reduced number of potential suspects.

The Technology in Practice

British police use the police national database (PND) to carry out retrospective facial recognition searches. This process involves comparing a “probe image” of a suspect against a repository of over 19 million custody photos to find potential matches.

Acknowledged Discrimination

The UK interior ministry conceded last week that the technology was flawed. This acknowledgment followed 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 stated it “took steps on the findings”.

“This raises the issue of whether this technology only becomes useful if users accept discrimination in ethnicity and gender. Operational ease is a weak argument for disregarding fundamental rights.”

Long-Standing Problem

Internal documents 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 mitigate the problem.

Senior officers were informed of the algorithmic discrimination in late 2024. The government-ordered NPL review concluded the system was more likely to suggest false positives for images depicting women, individuals of Black ethnicity, and those under 40 years old.

A Policy U-Turn

In reaction, the national police leadership body ordered that the confidence threshold required for potential matches be increased to a level where the disparity was significantly reduced.

However, this directive was reversed the following month after forces complained that the adjusted system was producing fewer “useful lines of inquiry”. NPCC documents show the stricter setting cut the proportion of searches resulting in possible identifications from 56% to a mere under 15%.

Severe Disparities

Although the Home Office and NPCC declined to specify what setting is currently used, the latest NPL study found the system could generate false positives for Black women nearly a hundred times more frequently than for white women at specific configurations.

The ministry commented on these results: “The testing found that in a specific scenarios the software is has a greater tendency to incorrectly include some population segments 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 significantly reduces the effect of bias across legally safeguarded attributes of ethnicity, generation and sex but had a significant negative impact on operational effectiveness”. The papers further note that police units argued that “a previously useful tool now delivered outcomes of questionable value”.

Wider Implementation Proposals

Meanwhile, the UK administration has launched a ten-week public review on its plans to widen the use of facial recognition technology. Policing minister the relevant minister has described the tool as the “most significant advance since genetic fingerprinting”.

Expert and Oversight Concerns

Abimbola Johnson, head of the independent scrutiny and oversight board for the police race action plan, said: “There was scant discussion through equality strategy sessions of the facial recognition rollout even with clear relevance with the plan’s concerns.

“These revelations demonstrate once again that the anti-racism commitments the police has undertaken via the race action plan are failing to be integrated into broader operations. Independent assessments have warned that new technologies are being rolled out in a context where racial disparities, inadequate oversight and poor data collection continue to exist.

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

Official Statement

A Home Office spokesperson said: “We takes the findings of the report with utmost gravity and we have already taken action. A updated software has been independently tested and procured, which has no statistically significant bias. It will be trialled early next year and will be undergo further assessment.

“Our priority is protecting the public. This revolutionary tool will assist police to put criminals and rapists behind bars. There is officer review in every step of the procedure and no arrest or charge would be taken without specialist personnel carefully reviewing the output.”