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Law enforcement agencies across the UK effectively campaigned to deploy a facial recognition system acknowledged as discriminatory against females, young people, and individuals from ethnic minority groups, after complaining that a less biased version generated fewer potential suspects.

How the System Works

British police utilize the police national database (PND) to carry out searches using historical face recognition. This procedure involves matching a “probe image” of a suspect against a repository of more than 19 million mugshots to identify possible hits.

Acknowledged Discrimination

The UK interior ministry admitted last week that the technology was flawed. This admission followed a study by the government's National Physical Laboratory determined it misidentified people of Black and Asian heritage and women at significantly higher rates than white men. The ministry stated it “took steps on the findings”.

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

Known Issue

Internal documents show that this discriminatory flaw has been recognized for over twelve months. Furthermore, police forces lobbied to reverse an initial decision that was designed to mitigate the problem.

Senior officers were notified of the algorithmic discrimination in late 2024. The Home Office-commissioned NPL review concluded the system was more likely to produce incorrect matches for images depicting women, individuals of Black ethnicity, and those aged 40 and under.

A Reversed Decision

In response, the national police leadership body ordered that the accuracy setting required for possible hits be increased to a level where the bias was significantly reduced.

However, this decision was reversed the next month following complaints from police that the adjusted system was generating fewer “investigative leads”. Internal records indicate the higher threshold cut the number of queries that yielded potential matches from 56% to a just under 15%.

Profound Inequalities

Although the authorities declined to specify what threshold is now in operation, the recent independent review found the system could produce incorrect matches for women of Black heritage nearly a hundred times more often than for white women at certain settings.

The Home Office commented on these results: “Our evaluation found that in a specific scenarios the algorithm is more likely to incorrectly include some population segments in its search results.”

Balancing Utility and Fairness

Describing the effect of the brief increase to the system's confidence threshold, the NPCC documents note: “The change greatly lessens the impact of bias across legally safeguarded attributes of ethnicity, age and sex but had a significant negative impact on operational effectiveness”. The documents add that police units complained that “a previously useful tool returned results of questionable value”.

Wider Implementation Proposals

Meanwhile, the government has opened a ten-week public review on its plans to widen the use of facial recognition technology. The minister for police the relevant minister has labeled the technology as the “most significant advance since genetic fingerprinting”.

Criticism from Advisors and Monitors

Abimbola Johnson, chair of the advisory panel for the police race action plan, said: “We observed very little discussion in race action plan meetings of the technology deployment despite obvious cross-over with the plan’s concerns.

“These revelations demonstrate once again that the pledges to combat discrimination policing has made via the equality initiative are failing to be integrated into broader operations. Independent assessments have warned that new technologies are being rolled out in a landscape where racial disparities, weak scrutiny and faulty information gathering continue to exist.

“Any use of facial recognition must meet strict national standards, be subject to external review, and prove it diminishes rather than exacerbates ethnic bias.”

Official Statement

A government representative said: “The Home Office treat the findings of the report seriously and we have already taken action. A updated software has been independently tested and procured, which has demonstrated no measurable discrimination. It will be tested early next year and will be undergo evaluation.

“The foremost aim is ensuring public safety. This revolutionary tool will support police to apprehend and prosecute offenders. There is human involvement in each stage of the procedure and no arrest or charge would be taken without specialist personnel meticulously examining the output.”