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Police forces across the UK effectively campaigned to deploy a face scanning system known to be discriminatory against women, young people, and members of ethnic minority groups, following complaints that a more accurate version generated a reduced number of investigative leads.

The Technology in Practice

British police utilize the national police database to carry out searches using historical face recognition. This procedure entails comparing a reference photograph of a suspect against a database of more than 19 million custody photos to find possible hits.

Acknowledged Discrimination

The UK interior ministry conceded last week that the technology was flawed. This admission followed 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 Home Office stated it “took steps on the findings”.

“It prompts the question of whether facial recognition only becomes useful if users tolerate discrimination in race and gender. Operational ease is a poor argument for disregarding fundamental rights.”

Known Issue

Official papers reveal that this bias has been known about for more than a year. Furthermore, police forces argued to overturn an initial decision that was designed to address the problem.

Police bosses were notified of the algorithmic discrimination in late 2024. The government-ordered laboratory study concluded the system was had a higher probability to produce false positives for photos of females, Black people, and those aged 40 and under.

A Reversed Decision

In response, the national police leadership body ordered that the accuracy setting required for potential matches be increased to a point where the disparity was greatly diminished.

However, this directive was overturned the following month after forces complained that the adjusted system was generating a lower number of “useful lines of inquiry”. Internal records show the stricter setting cut the number of queries resulting in potential matches from over half to a mere 14%.

Severe Disparities

Although the authorities declined to specify what threshold is now in operation, the latest NPL study found the system could produce incorrect matches for Black women nearly a hundred times more often than for Caucasian women at specific configurations.

The Home Office commented on these results: “Our evaluation identified that in a specific scenarios the algorithm is more likely to wrongly flag some population segments in its match reports.”

Balancing Utility and Fairness

Describing the impact of the brief increase to the system's confidence threshold, the police records state: “The change significantly reduces the effect of bias across protected characteristics of race, age and sex but had a substantially detrimental effect on operational effectiveness”. The documents add that forces argued that “a once effective tactic now delivered outcomes of questionable value”.

Wider Implementation Proposals

Meanwhile, the government has launched a two-and-a-half-month public review on its proposals to expand the use of biometric scanning systems. The minister for police Sarah Jones has described the technology as the “biggest breakthrough since DNA matching”.

Expert and Oversight Concerns

Abimbola Johnson, chair of the advisory panel for the national policing equality strategy, commented: “We observed very little consideration through race action plan meetings of the technology deployment despite clear relevance with the plan’s concerns.

“These revelations show yet again that the anti-racism commitments the police has undertaken via the race action plan are failing to be integrated into broader operations. Our reports have cautioned that new technologies are being implemented in a landscape where racial disparities, weak scrutiny and faulty information gathering continue to exist.

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

Home Office Response

A government representative stated: “We takes the conclusions of the report with utmost gravity and we have already taken action. A updated software has been independently tested and acquired, which has no statistically significant bias. It will be tested in the coming months and will be subject to further assessment.

“Our priority is protecting the public. This revolutionary tool will assist officers to apprehend and prosecute offenders. There is human involvement in each stage of the process and no further action would be pursued without trained officers meticulously examining the results.”