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Police forces across the UK effectively campaigned to use a face scanning system acknowledged as discriminatory against women, young people, and members of minority ethnic backgrounds, after complaining that a less biased version produced a reduced number of investigative leads.

The Technology in Practice

British police utilize the national police database to carry out searches using historical face recognition. This process entails matching a reference photograph of a suspect against a repository of more than 19 million custody photos to identify possible hits.

Admitted Bias

The UK interior ministry admitted last week that the system was flawed. This admission followed a study by the National Physical Laboratory (NPL) found it incorrectly matched people of Black and Asian heritage and women at significantly higher rates than white men. The Home Office 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 fundamental rights.”

Long-Standing Problem

Internal documents show that this bias has been known about 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 laboratory study concluded the system was more likely to produce incorrect matches for photos of females, Black people, and those aged 40 and under.

A Reversed Decision

In response, the National Police Chiefs’ Council (NPCC) mandated that the accuracy setting required for potential matches be increased to a level where the bias was significantly reduced.

However, this decision was overturned the following month following complaints from police that the adjusted system was producing a lower number of “useful lines of inquiry”. Internal records indicate the stricter setting cut the number of searches resulting in possible identifications from 56% to a mere 14%.

Profound Inequalities

Although the authorities refused to say what setting is currently used, the recent independent review found the system could produce incorrect matches for women of Black heritage almost 100 times more frequently than for white women at certain settings.

The Home Office stated on these findings: “Our evaluation identified that in a limited set of circumstances the software is more likely to incorrectly include some demographic groups in its match reports.”

Operational Effectiveness vs. Bias

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

Broader Rollout Plans

Meanwhile, the UK administration has launched a two-and-a-half-month public review on its plans to expand the use of facial recognition technology. Policing minister Sarah Jones has described the tool as the “biggest breakthrough since genetic fingerprinting”.

Expert and Oversight Concerns

Abimbola Johnson, chair of the advisory panel for the national policing equality strategy, said: “There was scant discussion in equality strategy sessions of the technology deployment even with obvious cross-over with the strategy's goals.

“These revelations show yet again that the pledges to combat discrimination policing has undertaken through the equality initiative are not being translated into wider practice. Our reports have cautioned that new technologies are being implemented in a landscape where ethnic inequalities, inadequate oversight and poor data collection continue to exist.

“All deployment of this technology must meet rigorous official guidelines, be independently scrutinised, and prove it reduces rather than compounds racial disparity.”

Official Statement

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

“Our priority is ensuring public safety. This revolutionary tool will support police to put criminals and rapists behind bars. There is human involvement in each stage of the procedure and no arrest or charge would be pursued without specialist personnel carefully reviewing the output.”