🔗 Share this article

Law enforcement agencies across the United Kingdom effectively campaigned to deploy a face scanning system known to be discriminatory against females, young people, and individuals from ethnic minority groups, after complaining that a less biased version produced a reduced number of potential suspects.

How the System Works

UK forces utilize the police national database (PND) to conduct searches using historical face recognition. This process entails matching a “probe image” of a person of interest against a repository of over 19 million custody photos to identify possible hits.

Acknowledged Discrimination

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

“It prompts the issue of whether facial recognition only becomes useful if users accept discrimination in race and gender. Operational ease is a poor argument for overriding fundamental rights.”

Long-Standing Problem

Internal documents show that this discriminatory flaw has been recognized for over twelve months. Furthermore, police forces argued to overturn an initial decision that was intended to address the problem.

Senior officers were notified of the system's bias in September 2024. The government-ordered laboratory study found the system was more likely to suggest false positives for images depicting females, Black people, and those aged 40 and under.

A Policy U-Turn

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

However, this directive was reversed the next month after forces complained that the adjusted system was producing a lower number of “investigative leads”. Internal records show the higher threshold cut the proportion of queries that yielded potential matches from 56% to a mere 14%.

Severe Disparities

Although the authorities declined to specify what setting is currently used, the recent independent review found the system could generate false positives for Black women almost 100 times more often than for Caucasian women at specific configurations.

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

Balancing Utility and Fairness

Outlining the effect of the temporary raise to the system's confidence threshold, the NPCC documents state: “The change greatly lessens the effect of discrimination across protected characteristics of ethnicity, generation and gender but had a significant negative impact on police efficiency”. The documents further note that forces argued that “a once effective tactic returned outcomes of limited benefit”.

Broader Rollout Plans

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

Expert and Oversight Concerns

Abimbola Johnson, head of the advisory panel for the police race action plan, commented: “There was very little consideration in race action plan meetings of the facial recognition rollout even with clear relevance with the strategy's goals.

“These revelations demonstrate once again that the anti-racism commitments the police has made through the equality initiative are failing to be integrated into broader operations. Our reports have warned that new technologies are being rolled out in a landscape where ethnic inequalities, inadequate oversight and faulty information gathering continue to exist.

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

Official Statement

A Home Office spokesperson said: “The Home Office treat the findings of the study with utmost gravity and we have implemented changes. 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.

“Our priority is protecting the public. This revolutionary tool will assist police to put criminals and rapists behind bars. There is human involvement in every step of the process and no further action would be taken without specialist personnel meticulously examining the results.”