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Police forces across the UK successfully lobbied to use a facial recognition system acknowledged as biased against females, youths, and individuals from ethnic minority groups, following complaints that a less biased version produced a reduced number of potential suspects.

How the System Works

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

Acknowledged Discrimination

The Home Office admitted last week that the technology was flawed. This acknowledgment came after a review by the National Physical Laboratory (NPL) found it incorrectly matched people of Black and Asian heritage and females at significantly higher rates than Caucasian males. The ministry said it “had acted on the findings”.

“This raises the question of whether this technology only becomes effective if users tolerate biases in ethnicity and gender. Convenience is a weak argument for disregarding fundamental rights.”

Long-Standing Problem

Internal documents show that this bias has been recognized for over twelve months. Furthermore, police forces argued to overturn an initial decision that was intended to address the problem.

Police bosses were informed of the algorithmic discrimination in late 2024. The government-ordered NPL review found the system was had a higher probability to suggest incorrect matches for images depicting women, individuals of Black ethnicity, and those aged 40 and under.

A Policy U-Turn

In reaction, the national police leadership body mandated that the accuracy setting required for possible hits be increased to a level where the bias was significantly reduced.

However, this decision was overturned the following month after forces complained that the modified technology was generating fewer “useful lines of inquiry”. Internal records show the stricter setting reduced the number of queries resulting in potential matches from over half to a mere 14%.

Profound Inequalities

Although the Home Office and NPCC declined to specify what setting is now in operation, the latest independent review 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 stated on these results: “Our evaluation identified that in a limited set of circumstances the software is more likely to wrongly flag some demographic groups in its search results.”

Operational Effectiveness vs. Bias

Outlining the impact of the temporary raise to the system's confidence threshold, the police records note: “The change significantly reduces the effect of discrimination across legally safeguarded attributes of race, age and gender but had a substantially detrimental effect on operational effectiveness”. The documents add that forces complained that “a previously useful tool now delivered outcomes of questionable value”.

Wider Implementation Proposals

Meanwhile, the UK administration 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 the relevant minister has described the tool as the “most significant advance since DNA matching”.

Criticism from Advisors and Monitors

The chair of a police oversight board, head of the independent scrutiny and oversight board for the police race action plan, commented: “There was scant consideration through equality strategy sessions of the facial recognition rollout despite clear relevance with the plan’s concerns.

“This disclosure show once again that the pledges to combat discrimination the police has undertaken via the race action plan are failing to be integrated into broader operations. Independent assessments have cautioned that innovative tools are being rolled out in a landscape where ethnic inequalities, inadequate oversight and poor data collection already persist.

“Any use of facial recognition must adhere to rigorous official guidelines, be subject to external review, and demonstrate it diminishes rather than exacerbates racial disparity.”

Official Statement

A government representative said: “We takes the conclusions of the report with utmost gravity and we have implemented changes. A updated software has been externally evaluated and procured, which has demonstrated no measurable discrimination. It will be tested in the coming months and will be subject to further assessment.

“Our priority is ensuring public safety. This revolutionary tool will support officers to apprehend and prosecute offenders. There is officer review in each stage of the procedure and no arrest or charge would be pursued without trained officers meticulously examining the results.”