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Police forces across the United Kingdom successfully lobbied to deploy a facial recognition system known to be discriminatory against females, young people, and individuals from minority ethnic backgrounds, following complaints that a more accurate version generated fewer potential suspects.

The Technology in Practice

British police use the national police database to carry out retrospective facial recognition searches. This procedure involves matching a “probe image” of a person of interest against a repository of more than 19 million mugshots to find possible hits.

Acknowledged Discrimination

The UK interior ministry admitted last week that the technology was flawed. This admission came after a review by the National Physical Laboratory (NPL) found it misidentified people of Black and Asian heritage and females at much greater frequency than Caucasian males. The ministry stated it “took steps on the findings”.

“It prompts the question of whether this technology only becomes useful if users accept discrimination in race and gender. Convenience is a weak argument for overriding basic freedoms.”

Long-Standing Problem

Internal documents show that this bias has been known about for over twelve months. Furthermore, police forces argued to overturn an earlier ruling that was designed to address the problem.

Police bosses were informed of the algorithmic discrimination in late 2024. The government-ordered NPL review found the system was had a higher probability to suggest incorrect matches for images depicting females, individuals of Black ethnicity, and those aged 40 and under.

A Policy U-Turn

In reaction, the National Police Chiefs’ Council (NPCC) mandated that the accuracy setting required for possible hits be raised to a level where the disparity was greatly diminished.

However, this decision was reversed the next month following complaints from police that the modified technology was generating a lower number of “investigative leads”. Internal records indicate the higher threshold cut the proportion of searches that yielded possible identifications from over half to a mere 14%.

Profound Inequalities

Although the Home Office and NPCC declined to specify what setting is currently used, the latest independent review found the system could produce false positives for Black women almost 100 times more frequently than for white women at certain settings.

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

Balancing Utility and Fairness

Describing the impact of the brief increase to the system's accuracy setting, the police records state: “The change significantly reduces the effect of discrimination across legally safeguarded attributes of race, age and gender but had a substantially detrimental effect on operational effectiveness”. The papers further note that forces argued that “a previously useful tool now delivered results of questionable value”.

Wider Implementation Proposals

Meanwhile, the UK administration has opened a ten-week public review on its proposals to expand the use of biometric scanning systems. Policing minister the relevant minister has labeled the technology as the “biggest breakthrough since DNA matching”.

Expert and Oversight Concerns

The chair of a police oversight board, chair of the independent scrutiny and oversight board for the national policing equality strategy, commented: “There was very little discussion in equality strategy sessions of the technology deployment even with clear relevance with the strategy's goals.

“These revelations show once again that the pledges to combat discrimination policing has made through the race action plan are not being translated into broader operations. Our reports have cautioned that new technologies are being implemented in a landscape where racial disparities, inadequate oversight and poor data collection already persist.

“Any use of facial recognition must meet rigorous official guidelines, be independently scrutinised, and demonstrate it reduces rather than exacerbates racial disparity.”

Official Statement

A government representative stated: “We treat the findings of the report with utmost gravity and we have implemented changes. A new algorithm has been independently tested 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 ensuring public safety. This gamechanging technology will assist police to apprehend and prosecute offenders. There is human involvement in every step of the process and no further action would be pursued without trained officers carefully reviewing the results.”