🔗 Share this article

Law enforcement agencies across the United Kingdom effectively campaigned to use a facial recognition system acknowledged as discriminatory against females, youths, and individuals from minority ethnic backgrounds, following complaints that a more accurate version produced a reduced number of investigative leads.

The Technology in Practice

British police use the national police database to conduct retrospective facial recognition searches. This procedure involves matching a reference photograph of a person of interest against a database of over 19 million mugshots to find possible hits.

Admitted Bias

The UK interior ministry admitted last week that the technology was flawed. This acknowledgment followed a study by the National Physical Laboratory (NPL) determined it misidentified people of Black and Asian heritage and females at significantly higher rates than white men. The Home Office stated it “took steps on the findings”.

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

Known Issue

Official papers show that this discriminatory flaw has been recognized for over twelve months. Furthermore, law enforcement lobbied to reverse an earlier ruling that was designed to mitigate the problem.

Senior officers were notified of the system's bias in late 2024. The government-ordered laboratory study concluded the system was more likely to produce incorrect matches for images depicting females, individuals of Black ethnicity, and those aged 40 and under.

A Policy U-Turn

In reaction, the national police leadership body mandated that the confidence threshold required for possible hits be raised to a point where the bias was significantly reduced.

However, this decision was reversed the next month after forces complained that the modified technology was generating a lower number of “useful lines of inquiry”. Internal records indicate the stricter setting cut the number of searches that yielded potential matches from 56% to a just 14%.

Severe Disparities

Although the Home Office and NPCC refused to say what setting is now in operation, the latest NPL study found the system could produce false positives for Black women almost 100 times more frequently than for Caucasian women at specific configurations.

The Home Office commented on these findings: “Our evaluation identified 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

Describing the effect of the temporary raise to the system's accuracy setting, the police records note: “This adjustment greatly lessens the impact of discrimination across protected characteristics of race, generation and sex but had a substantially detrimental effect on police efficiency”. The papers add that forces argued that “a previously useful tool returned outcomes of questionable value”.

Broader Rollout Plans

Meanwhile, the government has launched a ten-week public review on its plans to expand the use of facial recognition technology. The minister for police Sarah Jones has described the tool as the “most significant advance since genetic fingerprinting”.

Criticism from Advisors and Monitors

The chair of a police oversight board, head of the independent scrutiny and oversight board for the police race action plan, said: “There was very little consideration through race action plan meetings of the technology deployment even with obvious cross-over with the strategy's goals.

“These revelations show once again that the pledges to combat discrimination the police has undertaken through the equality initiative are failing to be integrated into wider practice. Independent assessments have cautioned that innovative tools are being rolled out in a landscape where racial disparities, inadequate oversight and poor data collection already persist.

“All deployment of this technology must adhere to rigorous official guidelines, be independently scrutinised, and prove it diminishes rather than exacerbates racial disparity.”

Home Office Response

A government representative said: “The Home Office takes the findings of the report with utmost gravity and we have already taken action. A updated software has been externally evaluated and acquired, which has no statistically significant bias. It will be tested early next year and will be undergo further assessment.

“Our priority is protecting the public. This gamechanging technology will support police to put criminals and rapists behind bars. There is human involvement in every step of the process and no further action would be pursued without specialist personnel carefully reviewing the results.”