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Police forces across the United Kingdom effectively campaigned to deploy a facial recognition system acknowledged as biased against women, youths, and members of minority ethnic backgrounds, after complaining that a more accurate version generated a reduced number of potential suspects.

How the System Works

UK forces utilize the police national database (PND) to carry out searches using historical face recognition. This procedure entails matching a “probe image” of a suspect against a repository of over 19 million mugshots to find potential matches.

Acknowledged Discrimination

The Home Office conceded last week that the technology was biased. This acknowledgment followed a review by the government's National Physical Laboratory found it incorrectly matched Black and Asian people and females at much greater frequency than white men. The Home Office said it “had acted on the findings”.

“This raises the issue of whether facial recognition only becomes useful if users tolerate biases in race and gender. Convenience is a weak argument for overriding basic freedoms.”

Long-Standing Problem

Official papers show that this discriminatory flaw has been recognized for over twelve months. Furthermore, law enforcement argued to overturn an initial decision that was designed to mitigate the problem.

Senior officers were informed of the system's bias in September 2024. The Home Office-commissioned NPL review concluded the system was more likely to produce false positives for photos of females, Black people, and those aged 40 and under.

A Reversed Decision

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

However, this directive was overturned the following month following complaints from police that the adjusted system was producing fewer “investigative leads”. Internal records show the stricter setting reduced the proportion of searches resulting in potential matches from over half to a just under 15%.

Severe Disparities

Although the Home Office and NPCC refused to say what setting is currently used, the recent NPL study found the system could produce false positives for women of Black heritage nearly a hundred times more often than for Caucasian women at specific configurations.

The ministry stated on these findings: “Our evaluation identified that in a limited set of circumstances the algorithm is more likely to incorrectly include some population segments in its match reports.”

Operational Effectiveness vs. Bias

Describing the impact of the temporary raise to the system's accuracy setting, the NPCC documents state: “This adjustment greatly lessens the effect of discrimination across legally safeguarded attributes of race, generation and gender but had a substantially detrimental effect on operational effectiveness”. The documents further note that police units argued that “a once effective tactic returned results of questionable value”.

Wider Implementation Proposals

Meanwhile, the government has launched a ten-week public review on its proposals to widen the use of facial recognition technology. Policing minister Sarah Jones has described the tool as the “biggest breakthrough since DNA matching”.

Criticism from Advisors and Monitors

The chair of a police oversight board, head of the advisory panel for the national policing equality strategy, commented: “We observed scant consideration through equality strategy sessions of the technology deployment despite clear relevance with the plan’s concerns.

“These revelations demonstrate yet again that the anti-racism commitments the police has made through the race action plan are failing to be integrated into wider practice. Independent assessments have warned that innovative tools are being implemented in a landscape where racial disparities, weak scrutiny and poor data collection already persist.

“Any use of facial recognition must meet rigorous official guidelines, be independently scrutinised, and demonstrate it diminishes rather than compounds racial disparity.”

Official Statement

A Home Office spokesperson stated: “We takes the findings of the report with utmost gravity and we have implemented changes. A new algorithm has been independently tested and procured, which has no statistically significant bias. It will be tested in the coming months and will be undergo further assessment.

“Our priority is protecting the public. This revolutionary tool will assist officers to put criminals and rapists behind bars. There is human involvement in every step of the process and no arrest or charge would be taken without specialist personnel meticulously examining the output.”