🔗 Share this article

Law enforcement agencies across the United Kingdom effectively campaigned to use a facial recognition system acknowledged as biased against women, young people, and individuals from minority ethnic backgrounds, following complaints that a more accurate version generated fewer potential suspects.

How the System Works

British police utilize the police national database (PND) to conduct retrospective facial recognition searches. This procedure entails comparing a “probe image” of a person of interest against a database of more than 19 million mugshots to identify potential matches.

Admitted Bias

The Home Office admitted last week that the technology was biased. This admission came after a study by the National Physical Laboratory (NPL) determined it misidentified people of Black and Asian heritage and women at significantly higher rates than Caucasian males. The Home Office stated it “took steps on the findings”.

“This raises the issue of whether facial recognition only becomes useful if users accept discrimination in ethnicity and sex. Convenience is a poor argument for disregarding basic freedoms.”

Long-Standing Problem

Official papers show that this bias has been recognized for over twelve months. Furthermore, police forces lobbied to reverse an earlier ruling that was designed to mitigate the problem.

Police bosses were informed of the system's bias in September 2024. The government-ordered NPL review concluded the system was had a higher probability to produce false positives for images depicting women, Black people, 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 potential matches be increased to a point where the bias was greatly diminished.

However, this decision was reversed the next month following complaints from police that the modified technology was producing a lower number of “investigative leads”. Internal records show the stricter setting reduced the number of searches that yielded possible identifications from 56% to a just 14%.

Severe Disparities

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

The ministry commented on these results: “The testing identified that in a limited set of circumstances the software is more likely to wrongly flag some demographic groups in its match reports.”

Balancing Utility and Fairness

Outlining the effect of the temporary raise to the system's accuracy setting, the NPCC documents note: “This adjustment greatly lessens the impact of discrimination across protected characteristics of race, generation and sex but had a substantially detrimental effect on police efficiency”. The papers further note that forces argued that “a once effective tactic returned results of questionable value”.

Wider Implementation Proposals

Meanwhile, the UK administration has launched a ten-week public review on its plans to expand the use of facial recognition technology. The minister for police the relevant minister has described the tool as the “biggest breakthrough since DNA matching”.

Expert and Oversight Concerns

Abimbola Johnson, head of the advisory panel for the police race action plan, said: “We observed very little discussion through race action plan meetings of the technology deployment despite clear relevance with the strategy's goals.

“This disclosure demonstrate yet again that the anti-racism commitments the police has undertaken via the race action plan are not being translated into wider practice. Our reports have cautioned that new technologies are being rolled out in a landscape where racial disparities, weak scrutiny and poor data collection already persist.

“Any use of this technology must adhere to rigorous official guidelines, be subject to external review, and prove it reduces rather than exacerbates ethnic bias.”

Official Statement

A government representative stated: “We treat the findings of the report with utmost gravity and we have already taken action. A updated software has been independently tested and acquired, which has demonstrated no measurable discrimination. It will be trialled in the coming months and will be undergo evaluation.

“The foremost aim is protecting the public. This revolutionary tool will support officers to put criminals and rapists behind bars. There is officer review in every step of the procedure and no further action would be taken without trained officers meticulously examining the output.”