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Law enforcement agencies across the United Kingdom effectively campaigned to use a facial recognition system known to be discriminatory against women, youths, and members of ethnic minority groups, following complaints that a more accurate version produced fewer potential suspects.

The Technology in Practice

UK forces use the police national database (PND) to conduct retrospective facial recognition searches. This procedure entails matching a reference photograph of a person of interest against a database of more than 19 million mugshots to identify possible hits.

Admitted Bias

The Home Office admitted last week that the system was biased. This acknowledgment came after a review by the National Physical Laboratory (NPL) 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 question of whether facial recognition only becomes effective if users tolerate discrimination in ethnicity and gender. Operational ease is a poor argument for overriding fundamental rights.”

Known Issue

Internal documents reveal that this bias has been recognized for more than a year. Furthermore, police forces argued to overturn an earlier ruling that was intended to mitigate the problem.

Police bosses were notified of the algorithmic discrimination 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 Policy U-Turn

In response, the national police leadership body mandated that the confidence threshold required for potential matches be raised to a point where the bias was greatly diminished.

However, this directive was reversed the next month following complaints from police that the modified technology was generating a lower number of “useful lines of inquiry”. Internal records indicate the stricter setting cut the number of queries resulting in possible identifications from over half to a mere 14%.

Severe Disparities

Although the authorities declined to specify what setting is currently used, the recent NPL study found the system could generate incorrect matches for Black women nearly a hundred times more frequently than for Caucasian women at specific configurations.

The Home Office commented on these findings: “Our evaluation identified that in a limited set of circumstances the software is has a greater tendency to incorrectly include some demographic groups in its match reports.”

Operational Effectiveness vs. Bias

Describing the impact of the brief increase to the system's accuracy setting, the NPCC documents note: “This adjustment significantly reduces the impact of bias across legally safeguarded attributes of ethnicity, generation and sex but had a significant negative impact on police efficiency”. The documents further note that forces argued that “a previously useful tool returned outcomes of limited benefit”.

Wider Implementation Proposals

Meanwhile, the UK administration has launched a ten-week consultation on its plans to expand the use of facial recognition technology. Policing minister the relevant minister has labeled 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 police race action plan, said: “There was scant discussion in equality strategy sessions of the facial recognition rollout despite obvious cross-over with the plan’s concerns.

“These revelations show yet again that the pledges to combat discrimination policing has made via the race action plan are not being translated into wider practice. Our reports have cautioned that innovative tools are being rolled out in a landscape where ethnic inequalities, inadequate oversight and faulty information gathering already persist.

“All deployment of facial recognition must adhere to rigorous official guidelines, be independently scrutinised, and prove it diminishes rather than exacerbates racial disparity.”

Official Statement

A Home Office spokesperson said: “We takes the conclusions of the study seriously and we have already taken action. A updated software has been independently tested and acquired, which has demonstrated no measurable discrimination. It will be tested early next year and will be subject to further assessment.

“The foremost aim is ensuring public safety. This gamechanging technology will assist police to put criminals and rapists behind bars. There is human involvement in every step of the procedure and no arrest or charge would be pursued without trained officers carefully reviewing the output.”