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Law enforcement agencies across the UK effectively campaigned to use a face scanning system acknowledged as biased against females, young people, and individuals from minority ethnic backgrounds, after complaining that a less biased version generated a reduced number of potential suspects.

The Technology in Practice

UK forces use the national police database to carry out retrospective facial recognition searches. This procedure involves matching a “probe image” of a suspect against a database of more than 19 million custody photos to find potential matches.

Acknowledged Discrimination

The Home Office admitted last week that the technology was flawed. This admission followed a study by the government's National Physical Laboratory determined it misidentified people of Black and Asian heritage and women at significantly higher rates than white men. The ministry said it “had acted on the findings”.

“This raises the question of whether facial recognition only becomes useful if users accept biases in ethnicity and gender. Operational ease is a weak argument for overriding basic freedoms.”

Long-Standing Problem

Official papers reveal that this discriminatory flaw has been known about for over twelve months. Furthermore, police forces lobbied to reverse an earlier ruling that was designed to address the problem.

Police bosses were notified of the system's bias in late 2024. The Home Office-commissioned laboratory study found the system was more likely to produce false positives for photos of women, Black people, and those under 40 years old.

A Reversed Decision

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

However, this decision was overturned the next month following complaints from police that the adjusted system was producing fewer “useful lines of inquiry”. NPCC documents indicate the higher threshold cut the number of searches that yielded potential matches from over half to a just 14%.

Severe Disparities

Although the Home Office and NPCC declined to specify what setting is currently used, the latest independent review discovered the system could generate false positives for women of Black heritage almost 100 times more often than for white women at specific configurations.

The ministry stated on these findings: “Our evaluation found that in a specific scenarios the software is more likely to incorrectly include some population segments in its match reports.”

Balancing Utility and Fairness

Outlining the effect of the temporary raise to the system's accuracy setting, the police records note: “This adjustment greatly lessens the impact of discrimination across protected characteristics of ethnicity, age and sex but had a substantially detrimental effect on operational effectiveness”. The documents add that police units argued that “a once effective tactic returned outcomes of questionable value”.

Broader Rollout Plans

Meanwhile, the UK administration has launched a two-and-a-half-month public review on its proposals to expand the use of biometric scanning systems. Policing minister the relevant minister has labeled the tool as the “biggest breakthrough since genetic fingerprinting”.

Criticism from Advisors and Monitors

Abimbola Johnson, head of the independent scrutiny and oversight board for the national policing equality strategy, said: “There was scant discussion through equality strategy sessions of the technology deployment despite obvious cross-over with the plan’s concerns.

“These revelations show once again that the anti-racism commitments the police has made via the race action plan are failing to be integrated into wider practice. Our reports have cautioned that new technologies are being rolled out in a landscape where racial disparities, weak scrutiny and faulty information gathering already persist.

“Any use of facial recognition must adhere to strict national standards, be independently scrutinised, and demonstrate it diminishes rather than compounds ethnic bias.”

Home Office Response

A government representative said: “We treat the findings of the report seriously and we have already taken action. A new algorithm has been externally evaluated and acquired, which has demonstrated no measurable discrimination. It will be tested in the coming months 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 human involvement in every step of the process and no further action would be taken without specialist personnel meticulously examining the results.”