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Police forces across the United Kingdom successfully lobbied to use a face scanning system known to be discriminatory against females, youths, and individuals from minority ethnic backgrounds, after complaining that a more accurate version generated a reduced number of potential suspects.

How the System Works

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

Admitted Bias

The Home Office admitted last week that the system was flawed. This admission 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 ministry said it “had acted on the findings”.

“It prompts the question of whether this technology only becomes useful if users accept biases in ethnicity and gender. Convenience is a weak argument for disregarding fundamental rights.”

Long-Standing Problem

Official papers show that this discriminatory flaw has been known about for over twelve months. Furthermore, law enforcement lobbied to reverse an initial decision that was designed to address the problem.

Police bosses were notified of the system's bias in late 2024. The government-ordered NPL review found the system was had a higher probability to produce incorrect matches for photos of women, individuals of Black ethnicity, and those under 40 years old.

A Reversed Decision

In reaction, the National Police Chiefs’ Council (NPCC) ordered that the accuracy setting required for potential matches be raised to a point where the bias was significantly reduced.

However, this decision was reversed the following month following complaints from police that the adjusted system was producing fewer “investigative leads”. Internal records show the higher threshold cut the number of queries resulting in potential matches from 56% to a just 14%.

Severe Disparities

Although the Home Office and NPCC declined to specify what setting is now in operation, the latest independent review discovered the system could generate false positives for women of Black heritage almost 100 times more frequently than for Caucasian women at specific configurations.

The Home Office stated on these findings: “Our evaluation identified that in a specific scenarios the software is has a greater tendency to incorrectly include some population segments in its match reports.”

Balancing Utility and Fairness

Outlining the effect of the temporary raise to the system's accuracy setting, the NPCC documents state: “This adjustment significantly reduces the impact of discrimination across legally safeguarded attributes of ethnicity, generation and sex but had a significant negative impact on operational effectiveness”. The papers further note that forces complained that “a previously useful tool now delivered outcomes of limited benefit”.

Broader Rollout Plans

Meanwhile, the UK administration has opened a ten-week consultation on its plans to expand the use of facial recognition technology. Policing minister the relevant minister has described the tool as the “biggest breakthrough since genetic fingerprinting”.

Expert and Oversight Concerns

The chair of a police oversight board, head of the independent scrutiny and oversight board for the national policing equality strategy, said: “We observed scant discussion through race action plan meetings of the technology deployment even with obvious cross-over with the strategy's goals.

“These revelations demonstrate once again that the anti-racism commitments the police has undertaken via the equality initiative are not being translated into broader operations. Independent assessments have cautioned that innovative tools are being implemented in a context where ethnic inequalities, weak scrutiny and poor data collection already persist.

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

Official Statement

A government representative 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 acquired, which has no statistically significant bias. It will be tested early next year and will be undergo evaluation.

“Our priority is ensuring public safety. This gamechanging technology will support officers to apprehend and prosecute offenders. There is human involvement in every step of the process and no arrest or charge would be taken without trained officers meticulously examining the output.”