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Police forces across the United Kingdom successfully lobbied to use a face scanning system known to be discriminatory against women, youths, and individuals from minority ethnic backgrounds, after complaining that a more accurate version generated a reduced number of investigative leads.

How the System Works

British police utilize the national police database to conduct retrospective facial recognition searches. This process involves comparing a reference photograph of a person of interest against a database of more than 19 million mugshots to identify possible hits.

Acknowledged Discrimination

The Home Office conceded last week that the technology was biased. This admission followed a study by the government's National Physical Laboratory found it misidentified people of Black and Asian heritage and women at much greater frequency than white men. The ministry stated it “took steps on the findings”.

“This raises the question of whether facial recognition only becomes effective if users tolerate biases in ethnicity and sex. Convenience is a poor argument for disregarding basic freedoms.”

Known Issue

Internal documents show that this discriminatory flaw has been recognized for over twelve months. Furthermore, police forces argued to overturn an earlier ruling that was designed to address the problem.

Senior officers were notified of the system's bias in late 2024. The government-ordered laboratory study found the system was had a higher probability to suggest incorrect matches for photos of women, individuals of Black ethnicity, and those under 40 years old.

A Policy U-Turn

In response, the national police leadership body mandated that the confidence threshold required for potential matches be raised to a point where the disparity was greatly diminished.

However, this directive was reversed the next month following complaints from police that the modified technology was generating a lower number of “investigative leads”. NPCC documents show the stricter setting reduced the number of searches that yielded potential matches from over half to a just 14%.

Severe Disparities

Although the authorities declined to specify what threshold is now in operation, the recent independent review found the system could generate false positives for women of Black heritage nearly a hundred times more frequently than for Caucasian women at certain settings.

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

Operational Effectiveness vs. Bias

Outlining the impact of the brief increase to the system's confidence threshold, the police records state: “The change significantly reduces the effect of discrimination across legally safeguarded attributes of race, generation and sex but had a substantially detrimental effect on police efficiency”. The documents further note that police units complained that “a previously useful tool now delivered results of questionable value”.

Wider Implementation Proposals

Meanwhile, the government has opened a two-and-a-half-month public review on its proposals to widen the use of facial recognition technology. The minister for police Sarah Jones has described the technology as the “biggest breakthrough since genetic fingerprinting”.

Criticism from Advisors and Monitors

Abimbola Johnson, chair of the independent scrutiny and oversight board for the national policing equality strategy, said: “There was scant discussion in race action plan meetings of the technology deployment even with obvious cross-over with the plan’s concerns.

“This disclosure show once again that the anti-racism commitments the police has undertaken through the race action plan are not being translated into wider practice. Independent assessments have warned that new technologies are being rolled out in a landscape where racial disparities, inadequate oversight and poor data collection already persist.

“All deployment of this technology must adhere to strict national standards, be independently scrutinised, and prove it reduces rather than exacerbates ethnic bias.”

Official Statement

A government representative said: “We treat the findings of the study seriously and we have implemented changes. A updated software has been independently tested and procured, which has no statistically significant bias. It will be tested early next year and will be undergo evaluation.

“The foremost aim is ensuring public safety. This gamechanging technology will support police to apprehend and prosecute offenders. There is human involvement in every step of the process and no further action would be pursued without specialist personnel carefully reviewing the output.”