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Law enforcement agencies across the UK successfully lobbied to deploy a face scanning system acknowledged as discriminatory against females, youths, and members of ethnic minority groups, following complaints that a less biased version produced fewer investigative leads.

How the System Works

UK forces utilize the national police database to conduct searches using historical face recognition. This process entails comparing a reference photograph of a person of interest against a database of more than 19 million custody photos to identify possible hits.

Acknowledged Discrimination

The UK interior ministry conceded last week that the technology was flawed. This acknowledgment followed a study by the government's National Physical Laboratory determined it incorrectly matched people of Black and Asian heritage and females at much greater frequency than white men. The ministry stated it “took steps on the findings”.

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

Long-Standing Problem

Internal documents reveal that this discriminatory flaw has been known about for more than a year. Furthermore, law enforcement argued to overturn an earlier ruling that was designed to mitigate the problem.

Police bosses were notified of the algorithmic discrimination in September 2024. The government-ordered laboratory study found the system was had a higher probability to produce false positives for photos of females, Black people, and those under 40 years old.

A Policy U-Turn

In reaction, the national police leadership body ordered that the confidence threshold required for possible hits be raised to a level where the disparity was greatly diminished.

However, this directive was reversed the next month after forces complained that the adjusted system was generating fewer “useful lines of inquiry”. Internal records show the stricter setting reduced the number of queries resulting in possible identifications from 56% to a mere 14%.

Profound Inequalities

Although the authorities declined to specify what threshold is now in operation, the recent NPL study discovered the system could produce false positives for women of Black heritage almost 100 times more often than for white women at certain settings.

The Home Office stated on these findings: “The testing found that in a limited set of circumstances the software is more likely to incorrectly include some demographic groups in its search results.”

Balancing Utility and Fairness

Describing the effect of the brief increase to the system's confidence threshold, the police records note: “The change greatly lessens the impact of bias across protected characteristics of ethnicity, generation and gender but had a substantially detrimental effect on operational effectiveness”. The papers add that police units argued that “a previously useful tool now delivered results of limited benefit”.

Broader Rollout Plans

Meanwhile, the government has launched a two-and-a-half-month public review on its proposals to expand the use of biometric scanning systems. The minister for police Sarah Jones has labeled the tool as the “biggest breakthrough since DNA matching”.

Criticism from Advisors and Monitors

Abimbola Johnson, head of the independent scrutiny and oversight board for the police race action plan, commented: “There was very little discussion through race action plan meetings of the facial recognition rollout despite clear relevance with the strategy's goals.

“These revelations show once again that the anti-racism commitments policing has made via the race action plan are failing to be integrated into wider practice. Independent assessments have warned that innovative tools are being rolled out in a landscape where racial disparities, weak scrutiny and faulty information gathering already persist.

“All deployment of this technology must adhere to rigorous official guidelines, be independently scrutinised, and prove it reduces rather than compounds ethnic bias.”

Official Statement

A Home Office spokesperson said: “The Home Office takes the findings of the report seriously and we have already taken action. A new algorithm has been independently tested and procured, which has demonstrated no measurable discrimination. It will be trialled in the coming months and will be undergo further assessment.

“The foremost aim is protecting the public. This revolutionary tool will assist police to put criminals and rapists behind bars. There is officer review in each stage of the process and no arrest or charge would be taken without specialist personnel meticulously examining the output.”