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Police forces across the UK effectively campaigned to deploy a face scanning system acknowledged as discriminatory against women, youths, and individuals from ethnic minority groups, following complaints that a more accurate version generated fewer potential suspects.

The Technology in Practice

British police utilize the police national database (PND) to conduct retrospective facial recognition searches. This procedure entails matching a reference photograph of a suspect against a repository of over 19 million mugshots to find potential matches.

Admitted Bias

The Home Office conceded last week that the system was flawed. This admission followed a review by the government's National Physical Laboratory determined it incorrectly matched people of Black and Asian heritage and females at much greater frequency than Caucasian males. The ministry stated it “had acted on the findings”.

“It prompts the issue of whether facial recognition only becomes effective if users tolerate biases in ethnicity and gender. Operational ease is a poor argument for disregarding fundamental rights.”

Known Issue

Internal documents reveal that this bias has been known about for more than a year. Furthermore, law enforcement lobbied to reverse an earlier ruling that was intended to address the problem.

Senior officers were notified of the algorithmic discrimination in September 2024. The Home Office-commissioned NPL review concluded the system was more likely to suggest incorrect matches 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 mandated that the accuracy setting required for potential matches be raised to a level where the disparity was significantly reduced.

However, this directive was reversed the following month following complaints from police that the modified technology was producing fewer “investigative leads”. Internal records indicate the stricter setting cut the proportion of queries that yielded potential matches from 56% to a just under 15%.

Profound Inequalities

Although the authorities declined to specify what threshold is currently used, the recent NPL study discovered the system could produce incorrect matches for women of Black heritage almost 100 times more often than for Caucasian women at certain settings.

The ministry commented on these findings: “Our evaluation found that in a specific scenarios the algorithm is more likely to incorrectly include some demographic groups in its match reports.”

Balancing Utility and Fairness

Describing the effect of the temporary raise to the system's accuracy setting, the NPCC documents state: “This adjustment 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 further note that police units argued that “a previously useful tool returned outcomes of questionable value”.

Wider Implementation Proposals

Meanwhile, the government has launched a two-and-a-half-month public review on its proposals to expand the use of facial recognition technology. Policing minister the relevant minister has labeled the tool as the “most significant advance since genetic fingerprinting”.

Criticism from Advisors and Monitors

Abimbola Johnson, chair of the independent scrutiny and oversight board for the national policing equality strategy, commented: “There was scant consideration in race action plan meetings of the facial recognition rollout even with obvious cross-over with the strategy's goals.

“These revelations show yet again that the anti-racism commitments policing has made through the equality initiative are failing to be integrated into broader operations. Independent assessments have cautioned that new technologies are being rolled out in a landscape where ethnic inequalities, weak scrutiny and poor data collection already persist.

“All deployment of facial recognition must adhere to strict national standards, be subject to external review, and prove it diminishes rather than compounds racial disparity.”

Official Statement

A Home Office spokesperson said: “We takes the conclusions of the report with utmost gravity and we have implemented changes. A updated software has been independently tested and acquired, which has demonstrated no measurable discrimination. It will be tested early next year and will be undergo evaluation.

“Our priority is ensuring public safety. This gamechanging technology will assist police to apprehend and prosecute offenders. There is human involvement in each stage of the procedure and no arrest or charge would be pursued without trained officers meticulously examining the output.”