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

How the System Works

British police utilize the national police database to conduct retrospective facial recognition searches. This procedure involves matching a “probe image” of a suspect against a repository of over 19 million custody photos to find potential matches.

Acknowledged Discrimination

The Home Office admitted last week that the system was biased. This acknowledgment followed a review by the government's National Physical Laboratory determined it misidentified people of Black and Asian heritage and females at much greater frequency than Caucasian males. The Home Office stated it “took steps on the findings”.

“This raises the question of whether facial recognition only becomes useful if users accept biases in ethnicity and gender. Convenience is a poor argument for overriding fundamental rights.”

Long-Standing Problem

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

Police bosses were notified of the algorithmic discrimination in late 2024. The Home Office-commissioned laboratory study found the system was more likely to suggest false positives for photos of women, Black people, and those under 40 years old.

A Reversed Decision

In reaction, the National Police Chiefs’ Council (NPCC) ordered that the confidence threshold required for possible hits be raised to a point where the disparity was significantly reduced.

However, this decision was reversed the following month after forces complained that the modified technology was producing fewer “investigative leads”. NPCC documents show the stricter setting cut the number of queries resulting in potential matches from over half to a just 14%.

Severe Disparities

Although the authorities declined to specify what setting is now in operation, the recent independent review found the system could generate false positives for Black women nearly a hundred times more frequently than for Caucasian women at certain settings.

The ministry stated on these results: “The testing found that in a specific scenarios the software is more likely to incorrectly include some demographic groups in its search results.”

Operational Effectiveness vs. Bias

Describing the effect of the temporary raise to the system's confidence threshold, the police records note: “This adjustment significantly reduces the effect of discrimination across legally safeguarded attributes of ethnicity, generation and sex but had a significant negative impact on police efficiency”. The papers add that police units complained that “a once effective tactic returned outcomes of questionable value”.

Wider Implementation Proposals

Meanwhile, the UK administration has launched a two-and-a-half-month public review on its plans to widen the use of facial recognition technology. Policing minister the relevant minister has described the technology as the “most significant advance since DNA matching”.

Expert and Oversight Concerns

Abimbola Johnson, chair of the independent scrutiny and oversight board for the police race action plan, commented: “There was scant consideration in race action plan meetings of the facial recognition rollout despite clear relevance with the strategy's goals.

“These revelations show yet again that the pledges to combat discrimination the police has made through the equality initiative are not being translated into wider practice. Our reports have warned that innovative tools are being implemented in a context where racial disparities, inadequate oversight and poor data collection continue to exist.

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

Official Statement

A Home Office spokesperson stated: “We takes the findings of the report seriously and we have already taken action. A new algorithm has been externally evaluated and acquired, which has no statistically significant bias. 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 assist police to put criminals and rapists behind bars. There is human involvement in every step of the procedure and no arrest or charge would be taken without trained officers carefully reviewing the output.”