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Police forces across the UK effectively campaigned to deploy a facial recognition system acknowledged as biased against females, youths, and members of minority ethnic backgrounds, following complaints that a more accurate version produced fewer potential suspects.

The Technology in Practice

British police utilize the police national database (PND) to carry out searches using historical face recognition. This procedure entails comparing a reference photograph of a suspect against a repository of more than 19 million mugshots to find possible hits.

Acknowledged Discrimination

The Home Office admitted last week that the technology was biased. This acknowledgment followed a review by the National Physical Laboratory (NPL) found it incorrectly matched people of Black and Asian heritage and women at much greater frequency than white men. The Home Office said it “took steps on the findings”.

“It prompts the issue of whether this technology only becomes useful if users accept biases in race and sex. Convenience is a poor argument for overriding fundamental rights.”

Long-Standing Problem

Official papers reveal that this discriminatory flaw has been recognized for over twelve months. Furthermore, law enforcement argued to overturn an earlier ruling that was intended to address the problem.

Police bosses were notified of the system's bias in late 2024. The Home Office-commissioned NPL review found the system was had a higher probability to suggest false positives for photos of women, Black people, and those aged 40 and under.

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 point where the bias was significantly reduced.

However, this directive was overturned the following month after forces complained that the modified technology was generating a lower number of “investigative leads”. NPCC documents show the stricter setting reduced the number of searches resulting in possible identifications from over half to a just 14%.

Severe Disparities

Although the authorities refused to say what setting is now in operation, the recent NPL study found the system could produce false positives for Black women almost 100 times more frequently than for Caucasian women at specific configurations.

The Home Office commented on these findings: “Our evaluation found that in a limited set of circumstances the software is has a greater tendency to incorrectly include some population segments in its match reports.”

Operational Effectiveness vs. Bias

Outlining the impact of the temporary raise to the system's accuracy setting, the NPCC documents note: “This adjustment greatly lessens the effect of bias across protected characteristics of ethnicity, generation and sex but had a substantially detrimental effect on operational effectiveness”. The documents further note that police units argued that “a previously useful tool now delivered outcomes of questionable value”.

Wider Implementation Proposals

Meanwhile, the government has launched a two-and-a-half-month consultation on its proposals to expand the use of facial recognition technology. Policing minister Sarah Jones has described the technology as the “most significant advance since DNA matching”.

Criticism from Advisors and Monitors

Abimbola Johnson, chair of the advisory panel for the national policing equality strategy, said: “We observed very little discussion in race action plan meetings of the facial recognition rollout despite clear relevance with the strategy's goals.

“This disclosure show once again that the anti-racism commitments policing has undertaken via the equality initiative are not being translated into broader operations. Independent assessments have cautioned that new technologies are being rolled out in a context where racial disparities, inadequate oversight and faulty information gathering continue to exist.

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

Official Statement

A Home Office spokesperson said: “The Home Office treat the findings of the study with utmost gravity and we have already taken action. A new algorithm has been externally evaluated and procured, which has no statistically significant bias. It will be trialled in the coming months and will be undergo further assessment.

“The foremost aim is ensuring public safety. This revolutionary tool will support 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 trained officers meticulously examining the output.”