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Police forces across the UK successfully lobbied to use a face scanning system known to be biased against females, young people, and individuals from ethnic minority groups, following complaints that a less biased version generated fewer investigative leads.

The Technology in Practice

UK forces utilize the national police database to conduct retrospective facial recognition searches. This process involves matching a reference photograph of a person of interest against a database of more than 19 million mugshots to identify potential matches.

Acknowledged Discrimination

The Home Office conceded last week that the technology was biased. This admission followed a study by the National Physical Laboratory (NPL) determined it incorrectly matched people of Black and Asian heritage and females at significantly higher rates than Caucasian males. The Home Office stated it “had acted on the findings”.

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

Known Issue

Official papers reveal that this bias has been known about for over twelve months. Furthermore, police forces lobbied to reverse an initial decision that was intended to mitigate the problem.

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

A Reversed Decision

In response, the national police leadership body mandated that the accuracy setting required for potential matches be increased to a point where the bias was significantly reduced.

However, this decision was overturned the following month after forces complained that the modified technology was generating fewer “investigative leads”. NPCC documents indicate the stricter setting reduced the number of queries that yielded potential matches from 56% to a just under 15%.

Profound Inequalities

Although the Home Office and NPCC declined to specify what setting is currently used, the recent independent review discovered the system could generate incorrect matches for women of Black heritage nearly a hundred times more frequently than for white women at specific configurations.

The Home Office commented on these results: “The testing identified that in a specific scenarios the software is more likely to incorrectly include some demographic groups in its match reports.”

Operational Effectiveness vs. Bias

Outlining the impact of the temporary raise to the system's confidence threshold, the police records state: “This adjustment significantly reduces the impact of discrimination across legally safeguarded attributes of race, generation and sex but had a substantially detrimental effect on operational effectiveness”. The documents add that forces argued that “a once effective tactic now delivered results of limited benefit”.

Broader Rollout Plans

Meanwhile, the government has opened a ten-week consultation on its proposals to widen the use of biometric scanning systems. The minister for police the relevant minister has labeled the technology as the “most significant advance since genetic fingerprinting”.

Criticism from Advisors and Monitors

Abimbola Johnson, head of the independent scrutiny and oversight board for the police race action plan, commented: “We observed scant consideration through equality strategy sessions of the facial recognition rollout despite clear relevance with the plan’s concerns.

“These revelations show once again that the pledges to combat discrimination the police has undertaken via the equality initiative are not being translated into broader operations. Our reports have warned that innovative tools are being rolled out in a landscape where ethnic inequalities, weak scrutiny and poor data collection continue to exist.

“All deployment of this technology must adhere to strict national standards, be independently scrutinised, and prove it reduces rather than exacerbates racial disparity.”

Official Statement

A government representative said: “We takes the conclusions of the study with utmost gravity and we have already taken action. A updated software has been independently tested and acquired, which has no statistically significant bias. It will be tested in the coming months and will be undergo evaluation.

“The foremost aim is protecting the public. This revolutionary tool will assist officers to put criminals and rapists behind bars. There is human involvement in each stage of the process and no further action would be taken without trained officers meticulously examining the output.”