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Police forces across the United Kingdom successfully lobbied to use a facial recognition system acknowledged as discriminatory against women, youths, and individuals from minority ethnic backgrounds, following complaints that a more accurate version generated fewer investigative leads.

The Technology in Practice

UK forces utilize the police national database (PND) to conduct searches using historical face recognition. This process entails comparing a “probe image” of a suspect against a repository of over 19 million mugshots to find possible hits.

Acknowledged Discrimination

The UK interior ministry admitted last week that the technology was flawed. This admission came after a study by the National Physical Laboratory (NPL) determined it misidentified people of Black and Asian heritage and women at much greater frequency than white men. The ministry stated it “took steps on the findings”.

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

Known Issue

Internal documents reveal that this bias has been recognized for more than a year. Furthermore, law enforcement argued to overturn an earlier ruling that was intended to address the problem.

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

A Reversed Decision

In response, the national police leadership body mandated that the accuracy setting required for potential matches be raised to a level where the bias was significantly reduced.

However, this decision was overturned the next month after forces complained that the adjusted system was producing a lower number of “investigative leads”. NPCC documents indicate the stricter setting cut the proportion of queries resulting in potential matches from 56% to a mere under 15%.

Profound Inequalities

Although the authorities refused to say what setting is currently used, the recent NPL study discovered the system could generate false positives for women of Black heritage nearly a hundred times more often than for Caucasian women at specific configurations.

The Home Office stated on these findings: “The testing found that in a specific scenarios the algorithm is more likely to incorrectly include some demographic groups in its search results.”

Balancing Utility and Fairness

Outlining the effect of the temporary raise to the system's accuracy setting, the police records note: “This adjustment greatly lessens the effect of bias across legally safeguarded attributes of ethnicity, generation and gender but had a significant negative impact on operational effectiveness”. The papers further note that police units complained that “a previously useful tool now delivered results of limited benefit”.

Wider Implementation Proposals

Meanwhile, the government has opened a ten-week consultation on its proposals to expand the use of facial recognition technology. The minister for police the relevant minister has labeled the technology as the “biggest breakthrough since DNA matching”.

Criticism from Advisors and Monitors

Abimbola Johnson, chair of the independent scrutiny and oversight board for the police race action plan, said: “We observed scant discussion in race action plan meetings of the technology deployment despite obvious cross-over with the strategy's goals.

“This disclosure demonstrate yet again that the anti-racism commitments policing has undertaken through the race action plan are failing to be integrated into wider practice. Independent assessments have cautioned that new technologies are being implemented in a landscape where racial disparities, weak scrutiny and faulty information gathering continue to exist.

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

Home Office Response

A Home Office spokesperson stated: “The Home Office treat the findings of the report with utmost gravity and we have implemented changes. A new algorithm has been externally evaluated and acquired, which has no statistically significant bias. It will be trialled in the coming months and will be undergo further assessment.

“The foremost aim is ensuring public safety. This gamechanging technology will assist officers to apprehend and prosecute offenders. There is human involvement in each stage of the process and no arrest or charge would be pursued without specialist personnel carefully reviewing the results.”