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Police forces across the United Kingdom successfully lobbied to deploy a face scanning system known to be discriminatory against females, young people, and individuals from minority ethnic backgrounds, after complaining that a more accurate version produced a reduced number of investigative leads.

How the System Works

British police utilize the police national database (PND) to carry out retrospective facial recognition searches. This procedure entails comparing a “probe image” of a suspect against a database of more than 19 million mugshots to identify possible hits.

Acknowledged Discrimination

The UK interior ministry conceded last week that the system was biased. This admission followed a study by the government's National Physical Laboratory determined it incorrectly matched people of Black and Asian heritage and females at significantly higher rates than white men. The Home Office said it “took steps on the findings”.

“It prompts the issue of whether facial recognition only becomes useful if users accept discrimination in ethnicity and gender. Operational ease is a weak argument for disregarding basic freedoms.”

Known Issue

Internal documents reveal that this bias has been known about for over twelve months. Furthermore, law enforcement argued to overturn an initial decision that was designed to mitigate the problem.

Police bosses were informed of the algorithmic discrimination in late 2024. The government-ordered laboratory study found the system was had a higher probability to produce incorrect matches 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 ordered that the accuracy setting required for possible hits be increased to a point where the bias was greatly diminished.

However, this decision was reversed the next month following complaints from police that the modified technology was producing a lower number of “investigative leads”. Internal records indicate the stricter setting cut the proportion of queries that yielded potential matches from over half to a just 14%.

Severe Disparities

Although the authorities declined to specify what setting is now in operation, the latest independent review discovered the system could generate incorrect matches for Black women almost 100 times more frequently than for Caucasian women at specific configurations.

The Home Office stated on these results: “The testing found that in a limited set of circumstances the software is has a greater tendency to incorrectly include some demographic groups in its search results.”

Operational Effectiveness vs. Bias

Outlining the effect of the brief increase to the system's confidence threshold, the police records state: “This adjustment greatly lessens the effect 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 complained that “a once effective tactic now delivered outcomes of questionable value”.

Wider Implementation Proposals

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 labeled the technology as the “biggest breakthrough since genetic fingerprinting”.

Expert and Oversight Concerns

Abimbola Johnson, chair of the independent scrutiny and oversight board for the national policing equality strategy, commented: “There was scant consideration in equality strategy sessions of the facial recognition rollout despite clear relevance with the plan’s concerns.

“These revelations show yet again that the anti-racism commitments policing has undertaken via the race action plan are failing to be integrated into broader operations. Independent assessments have warned that innovative tools are being rolled out in a context where racial disparities, inadequate oversight and faulty information gathering already persist.

“All deployment of this technology must meet strict national standards, be subject to external review, and prove it reduces rather than exacerbates racial disparity.”

Official Statement

A government representative stated: “We takes the conclusions of the report with utmost gravity and we have implemented changes. A new algorithm has been externally evaluated and procured, which has demonstrated no measurable discrimination. It will be trialled in the coming months and will be subject to evaluation.

“The foremost aim is protecting the public. This revolutionary tool will support officers to apprehend and prosecute offenders. There is officer review in every step of the process and no further action would be pursued without trained officers carefully reviewing the output.”