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Police forces across the United Kingdom effectively campaigned to use a face scanning system acknowledged as biased against females, young people, and individuals from minority ethnic backgrounds, after complaining that a more accurate version produced a reduced number of investigative leads.

The Technology in Practice

UK forces use the police national database (PND) to carry out searches using historical face recognition. This process entails matching a reference photograph of a suspect against a repository of over 19 million custody photos to identify possible hits.

Acknowledged Discrimination

The UK interior ministry admitted last week that the technology was biased. This acknowledgment came after a study by the government's National Physical Laboratory determined it incorrectly matched Black and Asian people and women at significantly higher rates than white men. The ministry said it “took steps on the findings”.

“This raises the issue of whether this technology only becomes useful if users accept discrimination in ethnicity and sex. Convenience is a weak argument for disregarding basic freedoms.”

Long-Standing Problem

Internal documents reveal that this bias has been known about for over twelve months. Furthermore, police forces lobbied to reverse an earlier ruling that was designed to address the problem.

Senior officers were informed of the system's bias in September 2024. The government-ordered laboratory study found the system was more likely to produce false positives for photos of women, Black people, and those under 40 years old.

A Reversed Decision

In response, the national police leadership body mandated that the accuracy setting required for possible hits be increased to a point where the bias was significantly reduced.

However, this directive was reversed the following month after forces complained that the adjusted system was generating fewer “useful lines of inquiry”. NPCC documents indicate the higher threshold reduced the number of searches that yielded possible identifications from over half to a mere 14%.

Severe Disparities

Although the Home Office and NPCC refused to say what setting is now in operation, the latest independent review discovered the system could produce incorrect matches for Black women almost 100 times more often than for white women at specific configurations.

The ministry commented on these findings: “The testing found 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 accuracy setting, the NPCC documents note: “This adjustment significantly reduces the effect of bias across protected characteristics of race, generation and gender but had a substantially detrimental effect on police efficiency”. The documents further note that forces complained that “a once effective tactic returned results of limited benefit”.

Wider Implementation Proposals

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

Expert and Oversight Concerns

The chair of a police oversight board, head of the advisory panel for the national policing equality strategy, commented: “There was very little discussion through race action plan meetings of the technology deployment despite clear relevance with the plan’s concerns.

“This disclosure show once 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 rolled out in a landscape where ethnic inequalities, inadequate oversight and poor data collection already persist.

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

Official Statement

A government representative stated: “We takes the conclusions of the report seriously and we have implemented changes. A updated software has been externally evaluated and acquired, which has demonstrated no measurable discrimination. It will be trialled in the coming months and will be undergo further assessment.

“The foremost aim is protecting the public. This revolutionary tool will support officers to apprehend and prosecute offenders. There is human involvement in each stage of the process and no further action would be taken without trained officers meticulously examining the output.”