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Law enforcement agencies across the United Kingdom successfully lobbied to use a facial recognition system acknowledged as discriminatory against women, youths, and individuals from ethnic minority groups, following complaints that a more accurate version generated a reduced number of potential suspects.

The Technology in Practice

British police utilize the national police database to conduct retrospective facial recognition searches. This procedure involves matching a “probe image” of a person of interest against a repository of more than 19 million custody photos to find potential matches.

Admitted Bias

The Home Office conceded last week that the system was biased. This acknowledgment came after a study by the National Physical Laboratory (NPL) determined it incorrectly matched people of Black and Asian heritage and females at significantly higher rates than Caucasian males. The ministry stated it “had acted on the findings”.

“This raises the issue of whether facial recognition only becomes effective if users accept biases in ethnicity and gender. Convenience is a poor argument for disregarding fundamental rights.”

Known Issue

Official papers reveal that this bias has been recognized for more than a year. Furthermore, police forces argued to overturn an earlier ruling that was intended to address the problem.

Senior officers were informed of the algorithmic discrimination in late 2024. The Home Office-commissioned laboratory study concluded the system was had a higher probability to produce false positives for photos of females, individuals of Black ethnicity, and those aged 40 and under.

A Reversed Decision

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

However, this directive was reversed the next month following complaints from police that the modified technology was producing fewer “useful lines of inquiry”. Internal records indicate the higher threshold reduced the proportion of searches that yielded possible identifications from 56% to a just under 15%.

Profound Inequalities

Although the Home Office and NPCC refused to say what setting is currently used, the latest independent review discovered the system could produce incorrect matches for women of Black heritage nearly a hundred times more often than for Caucasian women at certain settings.

The ministry stated on these findings: “Our evaluation identified that in a specific scenarios the algorithm is more likely to wrongly flag some population segments in its match reports.”

Operational Effectiveness vs. Bias

Outlining the impact of the temporary raise to the system's confidence threshold, the police records note: “The change greatly lessens the impact of bias across protected characteristics of race, age and gender but had a significant negative impact on police efficiency”. The documents add that forces argued that “a previously useful tool now delivered outcomes of limited benefit”.

Broader Rollout Plans

Meanwhile, the UK administration has opened a two-and-a-half-month consultation on its proposals to expand the use of biometric scanning systems. Policing minister Sarah Jones 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: “We observed scant discussion through equality strategy sessions of the facial recognition rollout even with obvious cross-over with the strategy's goals.

“This disclosure show yet again that the pledges to combat discrimination policing has undertaken via the equality initiative are not being translated into wider practice. Our reports have cautioned that new technologies are being rolled out in a landscape where racial disparities, weak scrutiny and faulty information gathering continue to exist.

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

Official Statement

A Home Office spokesperson stated: “We treat the conclusions of the report with utmost gravity and we have already taken action. A new algorithm has been externally evaluated and acquired, which has no statistically significant bias. It will be trialled early next year and will be undergo evaluation.

“Our priority is protecting the public. This gamechanging technology will assist officers to apprehend and prosecute offenders. There is officer review in each stage of the process and no further action would be taken without trained officers meticulously examining the results.”