🔗 Share this article

Law enforcement agencies across the UK successfully lobbied to use a facial recognition system known to be discriminatory against females, youths, and members of ethnic minority groups, after complaining that a less biased version generated fewer investigative leads.

How the System Works

British police use the national police database to conduct searches using historical face recognition. This procedure involves matching a reference photograph of a suspect against a repository of over 19 million mugshots to find potential matches.

Acknowledged Discrimination

The UK interior ministry admitted last week that the system was flawed. This admission followed a review by the government's National Physical Laboratory determined it misidentified 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”.

“It prompts the question of whether facial recognition only becomes effective if users accept discrimination in ethnicity and sex. Operational ease is a weak argument for overriding basic freedoms.”

Known Issue

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 intended to address the problem.

Senior officers were notified of the system's bias in late 2024. The Home Office-commissioned laboratory study found the system was had a higher probability to produce incorrect matches for photos of females, Black people, and those aged 40 and under.

A Policy U-Turn

In response, the national police leadership body mandated that the accuracy setting required for possible hits be raised to a level where the disparity was significantly reduced.

However, this directive was reversed the following month after forces complained that the adjusted system was producing a lower number of “investigative leads”. NPCC documents indicate the stricter setting reduced the proportion of queries that yielded potential matches from over half to a just under 15%.

Profound Inequalities

Although the Home Office and NPCC declined to specify what setting is now in operation, the latest NPL study found 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 ministry commented on these findings: “Our evaluation identified that in a limited set of circumstances the algorithm is more likely to incorrectly include some demographic groups in its search results.”

Balancing Utility and Fairness

Describing the effect of the temporary raise to the system's accuracy setting, the police records note: “The change greatly lessens the impact of discrimination across protected characteristics of ethnicity, age and gender but had a substantially detrimental effect on operational effectiveness”. The documents further note that forces complained that “a once effective tactic returned results of questionable value”.

Broader Rollout Plans

Meanwhile, the government has launched a two-and-a-half-month consultation on its plans to widen the use of biometric scanning systems. Policing minister the relevant minister has described the tool as the “most significant advance since genetic fingerprinting”.

Criticism from Advisors and Monitors

Abimbola Johnson, chair of the advisory panel for the police race action plan, said: “There was very little consideration through equality strategy sessions of the technology deployment despite obvious cross-over with the strategy's goals.

“These revelations demonstrate yet again that the pledges to combat discrimination the police has undertaken through the race action plan are failing to be integrated into wider practice. Independent assessments have cautioned that new technologies are being implemented in a landscape where racial disparities, weak scrutiny and poor data collection continue to exist.

“Any use of this technology must meet rigorous official guidelines, be subject to external review, and demonstrate it diminishes rather than exacerbates ethnic bias.”

Official Statement

A government representative said: “We treat the findings of the report with utmost gravity and we have implemented changes. A updated software has been externally evaluated and procured, which has demonstrated no measurable discrimination. It will be trialled in the coming months and will be subject to further assessment.

“The foremost aim is protecting the public. This revolutionary tool will assist police to apprehend and prosecute offenders. There is officer review in every step of the procedure and no arrest or charge would be pursued without specialist personnel meticulously examining the output.”