British Police Forces Campaign to Use Discriminatory Facial Recognition Technology

Police forces across the UK successfully lobbied to use a facial recognition system known to be biased against women, youths, and individuals from minority ethnic backgrounds, after complaining that a less biased version produced fewer potential suspects.

How the System Works

British police use the police national database (PND) to carry out searches using historical face recognition. This process involves matching a reference photograph of a suspect against a database of more than 19 million custody photos to find potential matches.

Admitted Bias

The UK interior ministry conceded last week that the technology was flawed. This admission came after a review by the National Physical Laboratory (NPL) determined it misidentified Black and Asian people and women at significantly higher rates than Caucasian males. The ministry stated it “took steps on the findings”.

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

Long-Standing Problem

Official papers show that this discriminatory flaw has been recognized for more than a year. Furthermore, police forces lobbied to reverse an initial decision that was intended to mitigate the problem.

Police bosses were notified of the algorithmic discrimination in late 2024. The government-ordered laboratory study found the system was had a higher probability to suggest incorrect matches for images depicting women, 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 increased to a level where the disparity was greatly diminished.

However, this decision was overturned the next month after forces complained that the modified technology was producing fewer “useful lines of inquiry”. NPCC documents show the stricter setting cut the number of queries resulting in possible identifications from over half to a just 14%.

Profound Inequalities

Although the Home Office and NPCC refused to say what setting is currently used, the latest independent review found the system could produce incorrect matches for women of Black heritage almost 100 times more frequently than for white women at specific configurations.

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

Balancing Utility and Fairness

Outlining the impact of the brief increase to the system's confidence threshold, the NPCC documents state: “The change greatly lessens the impact of discrimination across legally safeguarded attributes of race, generation and sex but had a significant negative impact on operational effectiveness”. The papers further note that police units argued that “a once effective tactic now delivered results of questionable value”.

Broader Rollout Plans

Meanwhile, the government has opened a ten-week public review on its plans to widen the use of biometric scanning systems. The minister for police the relevant minister has labeled the technology as the “biggest breakthrough since DNA matching”.

Criticism from Advisors and Monitors

Abimbola Johnson, head of the advisory panel for the police race action plan, said: “There was scant consideration through race action plan meetings of the facial recognition rollout even with obvious cross-over with the plan’s concerns.

“These revelations show yet again that the anti-racism commitments policing has made through the race action plan are failing to be integrated into wider practice. Our reports have cautioned that innovative tools are being rolled out in a context where ethnic inequalities, inadequate oversight and faulty information gathering already persist.

“All deployment of this technology must meet rigorous official guidelines, be independently scrutinised, and demonstrate it diminishes rather than exacerbates racial disparity.”

Official Statement

A government representative stated: “We takes the conclusions of the study seriously and we have already taken action. A updated software has been independently tested and procured, which has no statistically significant bias. It will be trialled early next year and will be subject to evaluation.

“The foremost aim is ensuring public safety. This gamechanging technology will assist police to apprehend and prosecute offenders. There is officer review in every step of the process and no arrest or charge would be taken without specialist personnel carefully reviewing the output.”