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Law enforcement agencies across the UK effectively campaigned to use a facial recognition system known to be biased against women, youths, and individuals from ethnic minority groups, following complaints that a less biased version produced fewer potential suspects.

How the System Works

British police utilize the police national database (PND) to carry out searches using historical face recognition. This process involves matching a reference photograph of a suspect against a repository of over 19 million custody photos to identify possible hits.

Admitted Bias

The UK interior ministry admitted last week that the system was biased. This acknowledgment followed a study by the government's National Physical Laboratory found it incorrectly matched people of Black and Asian heritage and women at much greater frequency than Caucasian males. The ministry said it “had acted on the findings”.

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

Known Issue

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

Senior officers were notified of the algorithmic discrimination in September 2024. The Home Office-commissioned laboratory study found the system was had a higher probability to produce false positives for photos of women, individuals of Black ethnicity, and those aged 40 and under.

A Policy U-Turn

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

However, this decision was overturned the following month after forces complained that the adjusted system was generating a lower number of “investigative leads”. NPCC documents show the stricter setting reduced the number of queries resulting in possible identifications from 56% to a just 14%.

Profound Inequalities

Although the authorities declined to specify what threshold is currently used, the latest NPL study found the system could produce incorrect matches for women of Black heritage nearly a hundred times more often than for Caucasian women at specific configurations.

The Home Office stated on these results: “Our evaluation identified that in a specific scenarios the algorithm is more likely to incorrectly include some demographic groups in its match reports.”

Balancing Utility and Fairness

Describing the impact of the temporary raise to the system's accuracy setting, the police records note: “This adjustment greatly lessens the impact of discrimination across protected characteristics of race, age and gender but had a significant negative impact on operational effectiveness”. The papers add that forces complained that “a once effective tactic now delivered results of questionable value”.

Wider Implementation Proposals

Meanwhile, the government has launched 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 tool as the “biggest breakthrough since DNA matching”.

Expert and Oversight Concerns

The chair of a police oversight board, chair of the advisory panel for the police race action plan, commented: “We observed very little consideration through race action plan meetings of the technology deployment even with clear relevance with the plan’s concerns.

“These revelations show once again that the pledges to combat discrimination the police has made through the equality initiative are not being translated into broader operations. Independent assessments have cautioned that new technologies are being rolled out in a landscape where racial disparities, inadequate oversight and faulty information gathering already persist.

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

Official Statement

A government representative stated: “The Home Office treat the conclusions of the study seriously and we have already taken action. A new algorithm has been independently tested and acquired, which has demonstrated no measurable discrimination. It will be tested in the coming months and will be undergo evaluation.

“Our priority is ensuring public safety. This revolutionary tool will assist police to apprehend and prosecute offenders. There is human involvement in every step of the process and no further action would be taken without trained officers meticulously examining the results.”