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Police forces across the United Kingdom successfully lobbied to use a face scanning system acknowledged as discriminatory against females, youths, and members of minority ethnic backgrounds, following complaints that a more accurate version produced fewer investigative leads.

The Technology in Practice

UK forces utilize the police national database (PND) to carry out searches using historical face recognition. This process entails comparing a “probe image” of a person of interest against a repository of over 19 million custody photos to identify possible hits.

Acknowledged Discrimination

The UK interior ministry conceded last week that the technology was biased. This admission came after a study by the National Physical Laboratory (NPL) found it misidentified people of Black and Asian heritage and women at much greater frequency than white men. The Home Office said it “had acted on the findings”.

“It prompts the question of whether this technology only becomes useful if users tolerate discrimination in race and sex. Operational ease is a weak argument for disregarding fundamental rights.”

Long-Standing Problem

Official papers show that this bias has been recognized for over twelve months. Furthermore, police forces lobbied to reverse an initial decision that was designed to address the problem.

Police bosses were informed of the algorithmic discrimination in late 2024. The Home Office-commissioned NPL review found the system was more likely to produce incorrect matches for photos of females, Black people, and those under 40 years old.

A Policy U-Turn

In response, the national police leadership body mandated that the accuracy setting required for potential matches be increased to a point where the disparity was greatly diminished.

However, this directive was reversed the next month after forces complained that the modified technology was generating fewer “useful lines of inquiry”. Internal records indicate the higher threshold cut the proportion of queries resulting in possible identifications from over half to a mere under 15%.

Severe Disparities

Although the authorities refused to say what threshold is now in operation, the recent independent review discovered the system could produce incorrect matches for Black women nearly a hundred times more often than for white women at specific configurations.

The Home Office stated on these results: “Our evaluation found that in a specific scenarios the software is has a greater tendency to wrongly flag some population segments in its match reports.”

Balancing Utility and Fairness

Describing the impact of the temporary raise to the system's accuracy setting, the police records note: “This adjustment significantly reduces the impact of bias across protected characteristics of race, generation and gender but had a substantially detrimental effect on police efficiency”. The documents add that forces complained that “a once effective tactic now delivered results of questionable value”.

Wider Implementation Proposals

Meanwhile, the UK administration has launched a two-and-a-half-month public review on its plans to widen the use of biometric scanning systems. Policing minister Sarah Jones has described the tool as the “biggest breakthrough since genetic fingerprinting”.

Criticism from Advisors and Monitors

The chair of a police oversight board, head of the advisory panel for the police race action plan, said: “There was scant discussion through equality strategy sessions of the technology deployment even with clear relevance with the plan’s concerns.

“This disclosure demonstrate once again that the pledges to combat discrimination the police has undertaken via the race action plan are failing to be integrated into broader operations. Our reports have warned that new technologies are being rolled out in a landscape where racial disparities, weak scrutiny and faulty information gathering continue to exist.

“All deployment of facial recognition must adhere to strict national standards, be independently scrutinised, and demonstrate it reduces rather than compounds ethnic bias.”

Official Statement

A Home Office spokesperson said: “The Home Office treat the findings of the report with utmost gravity and we have implemented changes. A updated software has been independently tested and acquired, which has no statistically significant bias. It will be tested early next year and will be undergo evaluation.

“The foremost aim is protecting the public. This gamechanging technology will support police to put criminals and rapists behind bars. There is officer review in each stage of the procedure and no further action would be taken without specialist personnel carefully reviewing the output.”