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Law enforcement agencies across the UK effectively campaigned to use a face scanning system acknowledged as discriminatory against females, youths, and individuals from ethnic minority groups, after complaining that a less biased version generated fewer potential suspects.

How the System Works

British police utilize the police national database (PND) to conduct retrospective facial recognition searches. This procedure involves matching a reference photograph of a person of interest against a database of over 19 million custody photos to find possible hits.

Acknowledged Discrimination

The UK interior ministry admitted last week that the technology was flawed. This acknowledgment came after a review by the National Physical Laboratory (NPL) found it misidentified Black and Asian people and females at significantly higher rates than white men. The ministry stated it “had acted on the findings”.

“It prompts the issue of whether facial recognition only becomes useful if users accept discrimination in race and gender. Convenience is a poor argument for disregarding fundamental rights.”

Known Issue

Official papers reveal that this discriminatory flaw has been known about for over twelve months. Furthermore, police forces lobbied to reverse an earlier ruling that was intended to address the problem.

Police bosses were informed of the algorithmic discrimination in late 2024. The government-ordered laboratory study concluded the system was had a higher probability to suggest incorrect matches for photos of women, individuals of Black ethnicity, and those under 40 years old.

A Policy U-Turn

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

However, this decision was overturned the next month following complaints from police that the adjusted system was generating fewer “investigative leads”. NPCC documents indicate the higher threshold reduced the number of queries resulting in potential matches from over half to a mere 14%.

Severe Disparities

Although the authorities refused to say what threshold is currently used, the recent NPL study found the system could produce false positives for Black women almost 100 times more often than for Caucasian women at specific configurations.

The ministry commented on these results: “Our evaluation identified that in a specific scenarios the algorithm is more likely to incorrectly include some demographic groups in its match reports.”

Operational Effectiveness vs. Bias

Describing the impact of the brief increase to the system's confidence threshold, the NPCC documents state: “This adjustment greatly lessens the impact of bias across legally safeguarded attributes of ethnicity, age and gender but had a significant negative impact on police efficiency”. The documents further note that forces complained that “a previously useful tool now delivered results of questionable value”.

Broader Rollout Plans

Meanwhile, the UK administration has launched a two-and-a-half-month public review on its plans to expand the use of facial recognition technology. Policing minister Sarah Jones has labeled the technology as the “most significant advance since DNA matching”.

Expert and Oversight Concerns

Abimbola Johnson, chair of the advisory panel for the police race action plan, commented: “We observed very little discussion through equality strategy sessions of the technology deployment even with obvious cross-over with the strategy's goals.

“These revelations demonstrate once again that the anti-racism commitments the police has undertaken via the equality initiative are not being translated into broader operations. Independent assessments have warned that new technologies are being rolled out in a landscape where ethnic inequalities, weak scrutiny and faulty information gathering already persist.

“All deployment of this technology must adhere to rigorous official guidelines, be independently scrutinised, and prove it diminishes rather than compounds ethnic bias.”

Official Statement

A government representative said: “The Home Office takes the findings of the report with utmost gravity and we have implemented changes. A new algorithm has been independently tested and acquired, which has demonstrated no measurable discrimination. It will be tested in the coming months and will be undergo evaluation.

“The foremost aim is protecting the public. This gamechanging technology will assist officers to apprehend and prosecute offenders. There is human involvement in every step of the process and no further action would be taken without specialist personnel meticulously examining the output.”