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Law enforcement agencies across the UK successfully lobbied to deploy a facial recognition system known to be biased against women, youths, and members of minority ethnic backgrounds, following complaints that a less biased version produced fewer investigative leads.

How the System Works

British police utilize the national police database to carry out retrospective facial recognition searches. This process involves comparing a reference photograph of a suspect against a database of more than 19 million custody photos to identify possible hits.

Acknowledged Discrimination

The UK interior ministry conceded last week that the system was flawed. This acknowledgment followed a review by the National Physical Laboratory (NPL) determined it misidentified people of Black and Asian heritage and females at significantly higher rates than Caucasian males. The Home Office said it “had acted on the findings”.

“This raises the issue of whether facial recognition only becomes effective if users accept biases in ethnicity and gender. Convenience is a weak argument for disregarding fundamental rights.”

Known Issue

Official papers show that this discriminatory flaw has been known about for over twelve months. Furthermore, law enforcement lobbied to reverse an initial decision that was intended to mitigate the problem.

Police bosses were notified of the system's bias in late 2024. The government-ordered laboratory study concluded the system was had a higher probability to suggest incorrect matches for images depicting females, individuals of Black ethnicity, and those under 40 years old.

A Policy U-Turn

In response, the national police leadership body ordered that the accuracy setting required for potential matches be increased to a level where the bias was greatly diminished.

However, this decision was reversed the next month after forces complained that the adjusted system was producing a lower number of “investigative leads”. Internal records indicate the stricter setting reduced the proportion of searches resulting in potential matches from 56% to a mere under 15%.

Severe Disparities

Although the Home Office and NPCC declined to specify what threshold is now in operation, the recent NPL study discovered the system could produce incorrect matches for women of Black heritage nearly a hundred times more frequently than for Caucasian women at specific configurations.

The Home Office stated on these findings: “Our evaluation 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

Outlining the impact of the temporary raise to the system's confidence threshold, the NPCC documents state: “The change significantly reduces the effect of discrimination across legally safeguarded attributes of race, generation and gender but had a significant negative impact on police efficiency”. The papers further note that police units complained that “a once effective tactic returned results of questionable value”.

Broader Rollout Plans

Meanwhile, the government has opened a two-and-a-half-month public review on its proposals to expand the use of facial recognition technology. The minister for police Sarah Jones has labeled the technology as the “most significant advance since genetic fingerprinting”.

Expert and Oversight Concerns

The chair of a police oversight board, chair of the independent scrutiny and oversight board for the national policing equality strategy, said: “We observed scant consideration in race action plan meetings of the technology deployment even with clear relevance with the strategy's goals.

“This disclosure demonstrate once again that the anti-racism commitments the police has made via the equality initiative are failing to be integrated into wider practice. Our reports have warned that new technologies are being rolled out in a landscape where ethnic inequalities, inadequate oversight and poor data collection continue to exist.

“Any use of this technology must meet strict national standards, be independently scrutinised, and prove it reduces rather than compounds ethnic bias.”

Home Office Response

A Home Office spokesperson said: “The Home Office treat the findings of the report seriously and we have implemented changes. A updated software has been independently tested and acquired, which has demonstrated no measurable discrimination. It will be trialled in the coming months and will be undergo evaluation.

“The foremost aim is protecting the public. This gamechanging technology will support officers 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.”