UK Police Forces Campaign to Use Biased Facial Recognition Technology

Law enforcement agencies across the UK effectively campaigned to deploy a face scanning system known to be discriminatory against women, young people, and individuals from minority ethnic backgrounds, after complaining that a less biased version produced fewer potential suspects.

How the System Works

British police utilize the police national database (PND) to conduct retrospective facial recognition searches. This process entails comparing a reference photograph of a suspect against a database of more than 19 million mugshots to identify possible hits.

Admitted Bias

The Home Office admitted last week that the system was flawed. This acknowledgment came after a review by the National Physical Laboratory (NPL) determined it incorrectly matched Black and Asian people and females at significantly higher rates than white men. The ministry stated it “took steps on the findings”.

“It prompts the issue of whether facial recognition only becomes useful if users tolerate discrimination in ethnicity and sex. Convenience is a weak argument for disregarding basic freedoms.”

Known Issue

Internal documents reveal that this bias has been recognized for over twelve months. Furthermore, law enforcement argued to overturn an earlier ruling that was designed to address the problem.

Police bosses were notified of the algorithmic discrimination in September 2024. The government-ordered NPL review found the system was more likely to produce false positives for photos of women, individuals of Black ethnicity, and those aged 40 and under.

A Reversed Decision

In response, the national police leadership body mandated that the accuracy setting required for potential matches be raised to a level where the bias was significantly reduced.

However, this directive was overturned the next month after forces complained that the modified technology was producing a lower number of “investigative leads”. Internal records indicate the stricter setting cut the proportion of searches that yielded possible identifications from over half to a just under 15%.

Severe Disparities

Although the authorities refused to say what threshold is now in operation, the latest independent review found the system could produce incorrect matches for women of Black heritage nearly a hundred times more frequently than for white women at certain settings.

The ministry commented on these findings: “Our evaluation found that in a limited set of circumstances the algorithm is more likely to incorrectly include some demographic groups in its match reports.”

Balancing Utility and Fairness

Outlining the impact of the temporary raise to the system's accuracy setting, the police records state: “This adjustment greatly lessens the effect of bias across protected characteristics of race, age and gender but had a significant negative impact on operational effectiveness”. The papers further note that forces complained that “a once effective tactic now delivered results of limited benefit”.

Wider Implementation Proposals

Meanwhile, the UK administration has launched a two-and-a-half-month public review on its proposals to widen the use of biometric scanning systems. The minister for police Sarah Jones has described the tool as the “most significant advance since genetic fingerprinting”.

Expert and Oversight Concerns

The chair of a police oversight board, head of the advisory panel for the national policing equality strategy, commented: “There was scant consideration through equality strategy sessions of the technology deployment despite clear relevance with the plan’s concerns.

“These revelations show yet again that the anti-racism commitments policing has made via the equality initiative are not being translated into wider practice. Independent assessments have cautioned that new technologies are being implemented in a context where racial disparities, weak scrutiny and faulty information gathering already persist.

“All deployment of this technology must meet strict national standards, be independently scrutinised, and prove it reduces rather than compounds racial disparity.”

Home Office Response

A government representative said: “We treat the conclusions of the report seriously and we have implemented changes. A new algorithm has been externally evaluated and procured, 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 police to put criminals and rapists behind bars. There is human involvement in each stage of the process and no further action would be taken without specialist personnel meticulously examining the output.”