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Police forces across the United Kingdom successfully lobbied to use a facial recognition system known to be discriminatory against females, young people, and members of ethnic minority groups, after complaining that a more accurate version generated fewer investigative leads.

How the System Works

UK forces use the national police database to conduct retrospective facial recognition searches. This process involves matching a reference photograph of a suspect against a repository of more than 19 million mugshots to identify possible hits.

Acknowledged Discrimination

The Home Office admitted last week that the system was flawed. This acknowledgment followed a review by the government's National Physical Laboratory found it misidentified Black and Asian people and females at significantly higher rates than Caucasian males. The Home Office stated it “took steps on the findings”.

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

Known Issue

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

Police bosses were informed of the system's bias in late 2024. The government-ordered laboratory study 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 response, the national police leadership body mandated that the confidence threshold required for potential matches be increased to a point where the bias was greatly diminished.

However, this decision was reversed the next month after forces complained that the adjusted system was generating fewer “useful lines of inquiry”. NPCC documents indicate the stricter setting reduced the proportion of queries resulting in possible identifications from 56% to a just 14%.

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 women of Black heritage almost 100 times more often than for white women at certain settings.

The ministry commented on these results: “The testing identified that in a limited set of circumstances the software is has a greater tendency to wrongly flag some demographic groups in its search results.”

Balancing Utility and Fairness

Outlining the impact of the brief increase to the system's accuracy setting, the NPCC documents state: “The change significantly reduces the impact of discrimination across legally safeguarded attributes of ethnicity, generation and sex but had a substantially detrimental effect on operational effectiveness”. The papers add that police units argued that “a once effective tactic now delivered outcomes of limited benefit”.

Broader Rollout Plans

Meanwhile, the government has launched a ten-week consultation on its proposals to expand the use of facial recognition technology. Policing minister the relevant minister has labeled the tool as the “most significant advance since DNA matching”.

Expert and Oversight Concerns

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

“This disclosure show once again that the anti-racism commitments policing has made through the race action plan are not being translated into wider practice. Independent assessments have cautioned that innovative tools are being implemented in a landscape where racial disparities, weak scrutiny and faulty information gathering continue to exist.

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

Official Statement

A government representative said: “We treat the findings 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 trialled early next year and will be undergo further assessment.

“Our priority is protecting the public. This gamechanging technology will assist officers to put criminals and rapists behind bars. There is officer review in every step of the process and no further action would be taken without trained officers meticulously examining the output.”