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Police forces across the United Kingdom successfully lobbied to deploy a face scanning system acknowledged as biased against females, young people, and individuals from ethnic minority groups, following complaints that a less biased version produced fewer investigative leads.

How the System Works

UK forces utilize the police national database (PND) to carry out retrospective facial recognition searches. This process involves matching a reference photograph of a suspect against a database of more than 19 million mugshots to find potential matches.

Acknowledged Discrimination

The UK interior ministry admitted last week that the technology was flawed. This admission followed a review by the National Physical Laboratory (NPL) determined it misidentified Black and Asian people and women at much greater frequency than white men. The ministry stated it “took steps on the findings”.

“It prompts the question of whether facial recognition only becomes effective if users accept biases in ethnicity and sex. Convenience is a weak argument for disregarding basic freedoms.”

Long-Standing Problem

Official papers reveal that this discriminatory flaw has been known about for over twelve months. Furthermore, police forces argued to overturn an earlier ruling that was designed to mitigate the problem.

Police bosses were informed of the system's bias in September 2024. The Home Office-commissioned NPL review concluded the system was had a higher probability to produce false positives for images depicting women, Black people, and those aged 40 and under.

A Policy U-Turn

In reaction, the national police leadership body ordered that the confidence threshold required for possible hits be raised to a level where the bias was greatly diminished.

However, this directive was reversed the next month following complaints from police that the adjusted system was producing a lower number of “investigative leads”. NPCC documents show the stricter setting cut the proportion of queries resulting in possible identifications from over half to a just under 15%.

Profound Inequalities

Although the authorities refused to say what setting is now in operation, the recent independent review found the system could produce false positives for Black women nearly a hundred times more frequently than for white women at certain settings.

The ministry commented on these findings: “The testing found that in a specific scenarios the software is has a greater tendency to wrongly flag some demographic groups in its search results.”

Operational Effectiveness vs. Bias

Describing the effect of the brief increase to the system's accuracy setting, the police records note: “The change significantly reduces the impact of bias across legally safeguarded attributes of race, generation and gender but had a significant negative impact on operational effectiveness”. The documents add that police units argued that “a previously useful tool returned outcomes of limited benefit”.

Wider Implementation Proposals

Meanwhile, the UK administration has opened a ten-week consultation on its proposals to expand the use of biometric scanning systems. The minister for police the relevant minister has described the technology as the “most significant advance since genetic fingerprinting”.

Criticism from Advisors and Monitors

The chair of a police oversight board, chair of the independent scrutiny and oversight board for the police race action plan, said: “We observed very little discussion through race action plan meetings of the facial recognition rollout even with clear relevance with the strategy's goals.

“This disclosure show yet again that the pledges to combat discrimination policing has made through the equality initiative are not being translated into broader operations. Our reports have warned that innovative tools are being rolled out in a context where ethnic inequalities, weak scrutiny and faulty information gathering already persist.

“Any use of this technology must meet rigorous official guidelines, be subject to external review, and prove it diminishes rather than exacerbates racial disparity.”

Official Statement

A Home Office spokesperson stated: “The Home Office takes the findings of the study with utmost gravity and we have already taken action. 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.

“Our priority is ensuring public safety. This gamechanging technology will support police to apprehend and prosecute offenders. There is officer review in every step of the procedure and no further action would be pursued without specialist personnel carefully reviewing the output.”