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Police forces across the UK effectively campaigned to deploy a face scanning system acknowledged as biased against females, young people, and members of minority ethnic backgrounds, following complaints that a less biased version produced fewer investigative leads.

How the System Works

UK forces utilize the police national database (PND) to conduct retrospective facial recognition searches. This process entails comparing a reference photograph of a person of interest against a repository of over 19 million mugshots to find possible hits.

Acknowledged Discrimination

The Home Office admitted last week that the system was flawed. This acknowledgment came after a study by the government's National Physical Laboratory found it misidentified Black and Asian people and females at much greater frequency than Caucasian males. The ministry said it “had acted on the findings”.

“It prompts the question of whether facial recognition only becomes effective if users tolerate biases in race and sex. Operational ease is a poor argument for overriding fundamental rights.”

Long-Standing Problem

Official papers reveal that this bias 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 system's bias in September 2024. The government-ordered NPL review concluded the system was more likely to suggest false positives for images depicting women, individuals of Black ethnicity, and those aged 40 and under.

A Reversed Decision

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

However, this directive was reversed the following month following complaints from police that the adjusted system was generating a lower number of “useful lines of inquiry”. NPCC documents indicate the stricter setting cut the number of queries that yielded possible identifications from over half to a just under 15%.

Profound Inequalities

Although the authorities declined to specify what setting is currently used, the recent independent review found the system could generate false positives for Black women nearly a hundred times more often than for white women at certain settings.

The Home Office stated on these results: “Our evaluation found that in a limited set of circumstances the algorithm is has a greater tendency to wrongly flag some population segments in its search results.”

Operational Effectiveness vs. Bias

Outlining the effect of the brief increase to the system's confidence threshold, 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 documents further note that forces argued that “a previously useful tool returned outcomes of limited benefit”.

Wider Implementation Proposals

Meanwhile, the government has opened a ten-week consultation on its proposals to expand the use of facial recognition technology. The minister for police Sarah Jones has labeled the tool as the “biggest breakthrough since genetic fingerprinting”.

Criticism from Advisors and Monitors

The chair of a police oversight board, head of the advisory panel for the national policing equality strategy, commented: “There was scant discussion in equality strategy sessions of the technology deployment even with obvious cross-over with the plan’s concerns.

“This disclosure show once again that the anti-racism commitments policing has undertaken through the equality initiative are not being translated into broader operations. Independent assessments have warned that new technologies are being implemented in a context where racial disparities, weak scrutiny and faulty information gathering already persist.

“Any use of facial recognition must meet strict national standards, be independently scrutinised, and prove it reduces rather than exacerbates ethnic bias.”

Official Statement

A government representative stated: “We takes the findings of the study 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.

“The foremost aim is ensuring public safety. This revolutionary tool will support officers to put criminals and rapists behind bars. There is human involvement in each stage of the process and no arrest or charge would be taken without specialist personnel meticulously examining the results.”