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Law enforcement agencies across the UK effectively campaigned to deploy a facial recognition system acknowledged as biased against women, youths, and members of ethnic minority groups, after complaining that a less biased version produced fewer potential suspects.

How the System Works

UK forces utilize the police national database (PND) to carry out searches using historical face recognition. This process entails comparing a “probe image” of a suspect against a database of more than 19 million mugshots to find possible hits.

Admitted Bias

The Home Office conceded last week that the system was biased. This acknowledgment came after a study by the National Physical Laboratory (NPL) found it incorrectly matched Black and Asian people and women at much greater frequency than white men. The ministry stated it “took steps on the findings”.

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

Long-Standing Problem

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

Senior officers were notified of the algorithmic discrimination in late 2024. The Home Office-commissioned laboratory study found the system was more likely to produce incorrect matches for images depicting women, Black people, and those under 40 years old.

A Policy U-Turn

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

However, this directive was overturned the following month after forces complained that the adjusted system was producing fewer “useful lines of inquiry”. Internal records show the stricter setting reduced the proportion of searches resulting in potential matches from 56% to a mere 14%.

Severe Disparities

Although the Home Office and NPCC declined to specify what setting 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 frequently than for Caucasian women at specific configurations.

The ministry commented on these findings: “The testing identified that in a specific scenarios the software is has a greater tendency to wrongly flag some population segments in its match reports.”

Balancing Utility and Fairness

Describing the impact of the brief increase to the system's confidence threshold, the police records note: “This adjustment significantly reduces the effect of discrimination across protected characteristics of ethnicity, age and gender but had a substantially detrimental effect on police efficiency”. The papers add that police units argued that “a previously useful tool now delivered outcomes 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. Policing minister Sarah Jones has labeled the technology as the “biggest breakthrough since DNA matching”.

Expert and Oversight Concerns

The chair of a police oversight board, head of the advisory panel for the national policing equality strategy, said: “There was scant consideration through race action plan meetings of the facial recognition rollout even with clear relevance with the plan’s concerns.

“This disclosure demonstrate once again that the anti-racism commitments the police has made via the equality initiative are not being translated into broader operations. Independent assessments have cautioned that new technologies are being implemented in a landscape where ethnic inequalities, inadequate oversight and faulty information gathering already persist.

“All deployment of this technology must adhere to rigorous official guidelines, be independently scrutinised, and prove it diminishes rather than compounds ethnic bias.”

Official Statement

A government representative stated: “We treat the findings of the report seriously and we have implemented changes. A new algorithm has been externally evaluated and procured, which has demonstrated no measurable discrimination. It will be tested early next year and will be undergo further assessment.

“The foremost aim 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 arrest or charge would be pursued without specialist personnel meticulously examining the results.”