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Police forces across the United Kingdom successfully lobbied to deploy a facial recognition system known to be discriminatory against females, youths, and individuals from minority ethnic backgrounds, following complaints that a more accurate version produced a reduced number of investigative leads.

How the System Works

UK forces utilize the police national database (PND) to carry out retrospective facial recognition searches. This procedure involves matching a reference photograph of a suspect against a database of over 19 million custody photos to find possible hits.

Acknowledged Discrimination

The UK interior ministry conceded last week that the system was flawed. This admission followed a review by the National Physical Laboratory (NPL) found it incorrectly matched people of Black and Asian heritage and women at much greater frequency than white men. The Home Office said it “took steps on the findings”.

“It prompts the question of whether facial recognition only becomes useful if users accept discrimination in ethnicity and gender. Convenience is a weak argument for overriding fundamental rights.”

Known Issue

Official papers show that this bias has been recognized for more than a year. Furthermore, law enforcement lobbied to reverse an initial decision that was intended to address the problem.

Police bosses were informed of the system's bias in September 2024. The government-ordered NPL review found the system was had a higher probability to suggest incorrect matches for photos of females, individuals of Black ethnicity, and those under 40 years old.

A Reversed Decision

In reaction, the national police leadership body ordered that the confidence threshold required for possible hits be raised to a level where the disparity was greatly diminished.

However, this decision was reversed the following month following complaints from police that the modified technology was producing a lower number of “useful lines of inquiry”. NPCC documents indicate the higher threshold reduced 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 recent NPL study discovered the system could produce incorrect matches for Black women 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 software is more likely to incorrectly include some demographic groups in its match reports.”

Balancing Utility and Fairness

Outlining the effect of the brief increase to the system's accuracy setting, the police records state: “The change significantly reduces the effect of discrimination across protected characteristics of ethnicity, generation and sex but had a significant negative impact on operational effectiveness”. The documents further note that forces complained that “a once effective tactic now delivered outcomes of limited benefit”.

Wider Implementation Proposals

Meanwhile, the UK administration has launched a ten-week consultation on its proposals to widen the use of facial recognition technology. Policing minister the relevant minister has labeled the tool as the “biggest breakthrough since DNA matching”.

Criticism from Advisors and Monitors

The chair of a police oversight board, chair of the independent scrutiny and oversight board for the police race action plan, commented: “There was scant consideration in race action plan meetings of the technology deployment despite obvious cross-over with the plan’s concerns.

“These revelations demonstrate once again that the anti-racism commitments policing has made through the equality initiative are not being translated into wider practice. Independent assessments have cautioned that new technologies are being implemented in a context where ethnic inequalities, weak scrutiny and faulty information gathering continue to exist.

“Any use of facial recognition must adhere to rigorous official guidelines, be subject to external review, and prove it reduces rather than compounds ethnic bias.”

Home Office Response

A Home Office spokesperson stated: “The Home Office takes the conclusions of the report seriously and we have already taken action. A new algorithm has been externally evaluated and acquired, which has demonstrated no measurable discrimination. It will be trialled in the coming months and will be subject to evaluation.

“Our priority is protecting the public. This revolutionary tool will assist officers to put criminals and rapists behind bars. There is human involvement in each stage of the process and no arrest or charge would be pursued without specialist personnel carefully reviewing the output.”