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Law enforcement agencies across the UK effectively campaigned to deploy a facial recognition system acknowledged as discriminatory against females, young people, and members of minority ethnic backgrounds, following complaints that a less biased version produced fewer potential suspects.

How the System Works

UK forces utilize the national police database to carry out searches using historical face recognition. This procedure entails comparing a reference photograph of a person of interest against a database of over 19 million custody photos to find potential matches.

Acknowledged Discrimination

The UK interior ministry admitted last week that the technology was biased. This admission followed a study by the National Physical Laboratory (NPL) found it misidentified Black and Asian people and females at much greater frequency than Caucasian males. The ministry said it “had acted on the findings”.

“This raises the question of whether facial recognition only becomes useful if users tolerate biases in race and gender. Convenience is a poor argument for overriding basic freedoms.”

Long-Standing Problem

Official papers reveal that this discriminatory flaw has been known about 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 system's bias in September 2024. The Home Office-commissioned NPL review concluded the system was had a higher probability to suggest incorrect matches for images depicting females, Black people, and those aged 40 and under.

A Policy U-Turn

In reaction, the National Police Chiefs’ Council (NPCC) ordered that the confidence threshold required for potential matches be raised to a level where the bias was significantly reduced.

However, this directive was overturned the next month after forces complained that the adjusted system was producing a lower number of “useful lines of inquiry”. Internal records indicate the higher threshold cut the proportion of searches that yielded potential matches from over half to a just under 15%.

Severe Disparities

Although the Home Office and NPCC refused to say what setting is currently used, the latest NPL study found the system could generate incorrect matches for Black women nearly a hundred times more frequently than for Caucasian women at specific configurations.

The Home Office commented on these findings: “The testing found that in a limited set of circumstances the software is has a greater tendency to wrongly flag some population segments in its match reports.”

Operational Effectiveness vs. Bias

Describing the effect of the brief increase to the system's confidence threshold, the NPCC documents state: “This adjustment greatly lessens the effect of discrimination across protected characteristics of ethnicity, generation and gender but had a significant negative impact on police efficiency”. The papers further note that forces complained that “a once effective tactic now delivered outcomes of questionable value”.

Broader Rollout Plans

Meanwhile, the government has opened a two-and-a-half-month consultation 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, chair of the advisory panel for the national policing equality strategy, said: “There was very little discussion in equality strategy sessions of the technology deployment even with clear relevance with the plan’s concerns.

“This disclosure demonstrate yet again that the pledges to combat discrimination the police has made via the race action plan are not being translated into wider practice. Our reports have warned that innovative tools are being rolled out in a context where racial disparities, inadequate oversight and poor data collection continue to exist.

“All deployment of facial recognition must meet strict national standards, be independently scrutinised, and prove it diminishes rather than exacerbates racial disparity.”

Official Statement

A Home Office spokesperson said: “The Home Office takes the findings of the study seriously and we have implemented changes. A updated software has been externally evaluated and procured, which has demonstrated no measurable discrimination. It will be trialled early next year and will be undergo evaluation.

“The foremost aim is protecting the public. This revolutionary tool will support officers to apprehend and prosecute offenders. There is human involvement in each stage of the procedure and no arrest or charge would be taken without trained officers meticulously examining the results.”