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Police forces across the UK effectively campaigned to deploy a face scanning system acknowledged as discriminatory against females, young people, and members of ethnic minority groups, following complaints that a more accurate version produced a reduced number of potential suspects.

The Technology in Practice

British police utilize the national police database to carry out retrospective facial recognition searches. This process entails matching a “probe image” of a suspect against a database of over 19 million mugshots to identify potential matches.

Acknowledged Discrimination

The UK interior ministry conceded last week that the technology was flawed. This admission followed a review by the government's National Physical Laboratory found it misidentified people of Black and Asian heritage and women at significantly higher rates than white men. The ministry said it “had acted on the findings”.

“This raises the issue of whether facial recognition only becomes useful if users tolerate biases in ethnicity and sex. Convenience is a weak argument for disregarding fundamental rights.”

Long-Standing Problem

Official papers reveal that this discriminatory flaw has been recognized for more than a year. Furthermore, law enforcement argued to overturn an earlier ruling that was designed to address the problem.

Police bosses were notified of the system's bias in late 2024. The government-ordered laboratory study found the system was more likely to suggest incorrect matches for images depicting women, individuals of Black ethnicity, and those aged 40 and under.

A Reversed Decision

In reaction, the National Police Chiefs’ Council (NPCC) ordered 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 next month following complaints from police that the modified technology was generating fewer “investigative leads”. Internal records show the higher threshold reduced the proportion of queries that yielded potential matches from 56% to a just under 15%.

Profound Inequalities

Although the authorities refused to say what setting is currently used, the latest independent review discovered the system could generate incorrect matches for women of Black heritage almost 100 times more frequently than for Caucasian women at certain settings.

The ministry stated on these findings: “The testing found that in a limited set of circumstances the algorithm is more likely to wrongly flag some demographic groups in its search results.”

Operational Effectiveness vs. Bias

Describing the impact of the temporary raise to the system's accuracy setting, the police records note: “The change significantly reduces the effect of discrimination across protected characteristics of race, age and sex but had a substantially detrimental effect on police efficiency”. The documents further note that forces argued that “a once effective tactic returned results of questionable value”.

Broader Rollout Plans

Meanwhile, the government has opened 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 police race action plan, commented: “We observed scant discussion through equality strategy sessions of the technology deployment despite clear relevance with the plan’s concerns.

“These revelations show once again that the pledges to combat discrimination the police has undertaken through the race action plan are failing to be integrated into wider practice. Independent assessments have warned that innovative tools are being rolled out in a context where racial disparities, 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 demonstrate it reduces rather than exacerbates ethnic bias.”

Official Statement

A Home Office spokesperson stated: “The Home Office treat the conclusions of the study seriously and we have implemented changes. A new algorithm has been externally evaluated and acquired, which has no statistically significant bias. It will be trialled early next year and will be subject to evaluation.

“Our priority is protecting the public. This revolutionary tool will support police to apprehend and prosecute offenders. There is officer review in each stage of the process and no further action would be taken without trained officers carefully reviewing the output.”