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Police forces across the UK effectively campaigned to deploy a face scanning system known to be biased against females, youths, and members of ethnic minority groups, following complaints that a less biased version generated fewer potential suspects.

How the System Works

British police utilize the national police database to conduct searches using historical face recognition. This procedure entails matching a reference photograph of a person of interest against a database of more than 19 million custody photos to find potential matches.

Acknowledged Discrimination

The UK interior ministry conceded last week that the system was flawed. This admission followed a study by the government's National Physical Laboratory determined it incorrectly matched Black and Asian people and women at significantly higher rates than Caucasian males. The ministry stated it “took steps on the findings”.

“This raises the issue of whether facial recognition only becomes useful if users tolerate biases in race and gender. Convenience is a poor argument for disregarding basic freedoms.”

Known Issue

Official papers show that this discriminatory flaw has been recognized for more than a year. Furthermore, law enforcement lobbied to reverse an initial decision that was intended to address the problem.

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

A Policy U-Turn

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

However, this directive was overturned the next month after forces complained that the modified technology was generating fewer “useful lines of inquiry”. Internal records indicate the higher threshold cut the proportion of searches that yielded possible identifications from 56% to a mere under 15%.

Profound Inequalities

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

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

Balancing Utility and Fairness

Outlining the effect of the temporary raise to the system's accuracy setting, the police records note: “The change significantly reduces the impact of discrimination across legally safeguarded attributes of ethnicity, age and gender but had a significant negative impact on police efficiency”. The papers further note that forces argued that “a once effective tactic returned outcomes of limited benefit”.

Wider Implementation Proposals

Meanwhile, the UK administration has launched a two-and-a-half-month public review on its plans to widen the use of biometric scanning systems. Policing minister Sarah Jones has described the technology 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, said: “We observed very little consideration through equality strategy sessions of the technology deployment even with clear relevance with the plan’s concerns.

“These revelations demonstrate once again that the anti-racism commitments the police has made through the race action plan are failing to be integrated into broader operations. Our reports have warned that innovative tools are being rolled out in a landscape where racial disparities, inadequate oversight and faulty information gathering already persist.

“Any use of this technology must meet strict national standards, 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 findings of the report seriously and we have implemented changes. A new algorithm has been independently tested and procured, which has demonstrated no measurable discrimination. It will be tested early next year and will be undergo further assessment.

“The foremost aim is ensuring public safety. This gamechanging technology will support officers to put criminals and rapists behind bars. There is officer review in every step of the procedure and no arrest or charge would be taken without specialist personnel carefully reviewing the results.”