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Law enforcement agencies across the United Kingdom successfully lobbied to use a facial recognition system acknowledged as discriminatory against females, young people, and individuals from minority ethnic backgrounds, following complaints that a less biased version generated fewer potential suspects.

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 person of interest against a database of over 19 million custody photos to find potential matches.

Admitted Bias

The UK interior ministry admitted last week that the system was flawed. This admission came after a study 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 “took steps on the findings”.

“This raises the question of whether this technology only becomes effective if users tolerate discrimination in ethnicity and gender. Operational ease is a poor argument for overriding fundamental rights.”

Long-Standing Problem

Internal documents show that this discriminatory flaw has been known about for over twelve months. Furthermore, police forces lobbied to reverse an initial decision that was designed to address the problem.

Police bosses were notified of the algorithmic discrimination in September 2024. The Home Office-commissioned NPL review concluded the system was had a higher probability to suggest incorrect matches for photos of females, Black people, and those under 40 years old.

A Reversed Decision

In reaction, the National Police Chiefs’ Council (NPCC) ordered that the confidence threshold required for possible hits be raised to a point where the bias was greatly diminished.

However, this directive was reversed the next month following complaints from police that the modified technology was generating fewer “investigative leads”. Internal records indicate the higher threshold reduced the number of searches resulting in possible identifications from over half to a mere under 15%.

Severe Disparities

Although the Home Office and NPCC declined to specify what threshold is now in operation, the latest NPL study discovered the system could generate incorrect matches for women of Black heritage nearly a hundred times more frequently than for white women at certain settings.

The Home Office stated on these results: “Our evaluation identified that in a specific scenarios the algorithm is has a greater tendency to wrongly flag some population segments in its search results.”

Operational Effectiveness vs. Bias

Outlining the impact of the temporary raise to the system's confidence threshold, the NPCC documents state: “This adjustment significantly reduces the effect of bias across legally safeguarded attributes of race, generation and gender but had a substantially detrimental effect on police efficiency”. The documents add that police units complained that “a previously useful tool now delivered outcomes of questionable value”.

Broader Rollout Plans

Meanwhile, the UK administration has launched a ten-week public review on its proposals to widen the use of biometric scanning systems. Policing minister the relevant minister has labeled the technology as the “most significant advance since genetic fingerprinting”.

Expert and Oversight Concerns

Abimbola Johnson, chair of the advisory panel for the police race action plan, commented: “We observed scant consideration through race action plan meetings of the technology deployment even with obvious cross-over with the plan’s concerns.

“This disclosure show yet 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 implemented in a context where ethnic inequalities, inadequate oversight and faulty information gathering continue to exist.

“All deployment of facial recognition must adhere to rigorous official guidelines, be subject to external review, and prove it diminishes rather than compounds racial disparity.”

Home Office Response

A government representative stated: “We takes the conclusions of the report seriously and we have implemented changes. A updated software has been externally evaluated and acquired, which has no statistically significant bias. It will be tested early next year and will be subject to evaluation.

“The foremost aim is protecting the public. This revolutionary tool will support officers to apprehend and prosecute offenders. There is human involvement in every step of the process and no further action would be pursued without trained officers carefully reviewing the results.”