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Law enforcement agencies across the United Kingdom effectively campaigned to deploy a face scanning system known to be biased against women, youths, and individuals from ethnic minority groups, following complaints that a more accurate version produced a reduced number of investigative leads.

How the System Works

British police use the national police database to carry out retrospective facial recognition searches. This procedure entails comparing a reference photograph of a person of interest against a database of more than 19 million mugshots to identify potential matches.

Acknowledged Discrimination

The UK interior ministry admitted last week that the technology was biased. This admission followed a review by the National Physical Laboratory (NPL) found it incorrectly matched people of Black and Asian heritage and females at significantly higher rates than Caucasian males. The Home Office stated it “took steps on the findings”.

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

Long-Standing Problem

Internal documents show that this bias has been recognized for over twelve months. Furthermore, law enforcement 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 concluded the system was more likely to produce false positives for images depicting women, individuals of Black ethnicity, and those under 40 years old.

A Policy U-Turn

In reaction, the National Police Chiefs’ Council (NPCC) mandated that the accuracy setting required for possible hits be increased to a point where the bias was significantly reduced.

However, this decision was reversed the following month following complaints from police that the adjusted system was producing fewer “investigative leads”. NPCC documents show the stricter setting reduced the proportion of searches resulting in possible identifications from 56% to a just under 15%.

Severe Disparities

Although the authorities refused to say what setting is now in operation, the recent independent review found the system could produce incorrect matches for women of Black heritage almost 100 times more frequently than for white women at certain settings.

The ministry stated on these results: “Our evaluation found that in a specific scenarios the software is has a greater tendency to wrongly flag some population segments in its search results.”

Balancing Utility and Fairness

Outlining the impact of the temporary raise to the system's accuracy setting, the police records state: “The change significantly reduces the impact of discrimination across legally safeguarded attributes of ethnicity, generation and gender but had a significant negative impact on operational effectiveness”. The documents add that police units complained that “a previously useful tool returned results of questionable value”.

Wider Implementation Proposals

Meanwhile, the government has launched a ten-week public review on its plans to expand the use of biometric scanning systems. The minister for police Sarah Jones has described the tool as the “most significant advance since DNA matching”.

Criticism from Advisors and Monitors

The chair of a police oversight board, chair of the advisory panel for the national policing equality strategy, commented: “There was scant discussion through equality strategy sessions of the facial recognition rollout even with obvious cross-over with the strategy's goals.

“This disclosure show once again that the pledges to combat discrimination the police has made via the race action plan are failing to be integrated into wider practice. Independent assessments have warned that new technologies are being rolled out in a context where racial disparities, weak scrutiny and poor data collection already persist.

“Any use of this technology must meet strict national standards, be subject to external review, and demonstrate it diminishes rather than exacerbates racial disparity.”

Home Office Response

A Home Office spokesperson said: “The Home Office treat the conclusions of the study with utmost gravity and we have already taken action. A updated software has been externally evaluated 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 protecting the public. This gamechanging technology will support officers to apprehend and prosecute offenders. There is officer review in every step of the process and no further action would be taken without trained officers carefully reviewing the output.”