UK Police Forces Lobbied to Use Discriminatory Facial Recognition Technology

Police forces across the United Kingdom effectively campaigned to deploy a facial recognition system known to be biased against females, young people, and members of ethnic minority groups, following complaints that a more accurate version produced fewer potential suspects.

How the System Works

UK forces use the police national database (PND) to carry out retrospective facial recognition searches. This procedure entails matching a “probe image” of a suspect against a database of more than 19 million mugshots to find potential matches.

Admitted Bias

The Home Office admitted last week that the technology was flawed. This acknowledgment came after a review by the National Physical Laboratory (NPL) determined it misidentified people of Black and Asian heritage and females at much greater frequency than Caucasian males. The Home Office said it “took steps on the findings”.

“It prompts the question of whether this technology only becomes effective if users tolerate biases in race and sex. Convenience is a poor argument for disregarding fundamental rights.”

Known Issue

Official papers reveal that this discriminatory flaw has been known about for more than a year. Furthermore, law enforcement lobbied to reverse an earlier ruling that was designed to address the problem.

Senior officers were informed of the algorithmic discrimination in September 2024. The government-ordered NPL review concluded the system was more likely to produce false positives for photos of women, Black people, and those aged 40 and under.

A Policy U-Turn

In reaction, the National Police Chiefs’ Council (NPCC) mandated that the confidence threshold required for possible hits be increased to a level where the bias was significantly reduced.

However, this decision was overturned the next month after forces complained that the modified technology was producing a lower number of “investigative leads”. Internal records show the stricter setting reduced the number of searches that yielded possible identifications from 56% to a mere 14%.

Severe Disparities

Although the authorities declined to specify what setting is now in operation, the latest NPL study found the system could produce false positives for Black women nearly a hundred times more frequently than for white women at certain settings.

The Home Office commented on these findings: “Our evaluation identified that in a limited set of circumstances the software is has a greater tendency to wrongly flag some demographic groups in its match reports.”

Balancing Utility and Fairness

Describing the effect of the brief increase to the system's confidence threshold, the police records state: “This adjustment greatly lessens the effect of bias across legally safeguarded attributes of race, generation and gender but had a substantially detrimental effect on police efficiency”. The papers further note that police units complained that “a previously useful tool now delivered outcomes of questionable value”.

Broader Rollout Plans

Meanwhile, the government has launched a two-and-a-half-month public review on its plans to widen 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 in race action plan meetings of the facial recognition rollout even with obvious cross-over with the plan’s concerns.

“These revelations demonstrate yet again that the anti-racism commitments policing has undertaken via the race action plan are not being translated into broader operations. Our reports have warned that innovative tools are being rolled out in a landscape where racial disparities, inadequate oversight and poor data collection continue to exist.

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

Official Statement

A Home Office spokesperson stated: “We takes the conclusions of the study seriously and we have already taken action. A new algorithm has been independently tested and procured, which has demonstrated no measurable discrimination. It will be trialled in the coming months and will be subject to 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 every step of the procedure and no arrest or charge would be pursued without trained officers meticulously examining the output.”