🔗 Share this article

Law enforcement agencies across the UK successfully lobbied to deploy a facial recognition system known to be discriminatory against females, youths, and individuals from ethnic minority groups, after complaining that a more accurate version produced a reduced number of potential suspects.

How the System Works

UK forces use the police national database (PND) to carry out retrospective facial recognition searches. This procedure entails comparing a reference photograph of a person of interest against a database of more than 19 million mugshots to find potential matches.

Admitted Bias

The UK interior ministry conceded last week that the technology was flawed. This acknowledgment followed a study by the National Physical Laboratory (NPL) determined it incorrectly matched Black and Asian people and women at much greater frequency than white men. The Home Office said it “took steps on the findings”.

“It prompts the question of whether this technology only becomes useful if users accept discrimination in race and gender. Convenience is a poor argument for overriding basic freedoms.”

Long-Standing Problem

Official papers show that this discriminatory flaw has been known about for over twelve months. Furthermore, law enforcement argued to overturn an earlier ruling that was intended to mitigate the problem.

Police bosses were notified of the system's bias in September 2024. The government-ordered laboratory study concluded the system was more likely to produce false positives for images depicting women, individuals of Black ethnicity, and those aged 40 and under.

A Policy U-Turn

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

However, this directive was reversed the next month after forces complained that the modified technology was producing a lower number of “useful lines of inquiry”. NPCC documents indicate the stricter setting reduced the number of queries resulting in potential matches from 56% to a just under 15%.

Severe Disparities

Although the Home Office and NPCC refused to say what threshold is currently used, the recent NPL study discovered the system could generate incorrect matches for Black women nearly a hundred times more frequently than for Caucasian women at specific configurations.

The Home Office stated on these results: “The testing found that in a limited set of circumstances the algorithm is more likely to wrongly flag some population segments in its match reports.”

Operational Effectiveness vs. Bias

Outlining the impact of the brief increase to the system's accuracy setting, the police records note: “This adjustment greatly lessens the impact of bias across legally safeguarded attributes of ethnicity, generation and sex but had a substantially detrimental effect on police efficiency”. The papers add that police units complained that “a once effective tactic now delivered results of limited benefit”.

Wider Implementation Proposals

Meanwhile, the UK administration has launched a two-and-a-half-month public review on its proposals to widen the use of facial recognition technology. Policing minister the relevant minister has labeled the technology as the “biggest breakthrough since DNA matching”.

Criticism from Advisors and Monitors

The chair of a police oversight board, chair of the independent scrutiny and oversight board for the national policing equality strategy, said: “There was scant discussion in equality strategy sessions of the facial recognition rollout even with clear relevance with the plan’s concerns.

“These revelations demonstrate yet again that the anti-racism commitments policing has made through the equality initiative are not being translated into wider practice. Independent assessments have cautioned that new technologies are being rolled out in a context where ethnic inequalities, weak scrutiny and faulty information gathering continue to exist.

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

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 tested early next year and will be undergo further assessment.

“Our priority is ensuring public safety. This gamechanging technology will support officers to put criminals and rapists behind bars. There is officer review in each stage of the procedure and no arrest or charge would be pursued without trained officers meticulously examining the results.”