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Police forces across the United Kingdom effectively campaigned to use a facial recognition system acknowledged as biased against females, young people, and individuals from ethnic minority groups, following complaints that a more accurate version produced fewer potential suspects.

How the System Works

UK forces utilize the national police database to conduct searches using historical face recognition. This process entails matching a reference photograph of a person of interest against a database of more than 19 million mugshots to find possible hits.

Admitted Bias

The Home Office conceded last week that the system was flawed. This acknowledgment followed a study by the government's National Physical Laboratory found it misidentified people of Black and Asian heritage and females at significantly higher rates than Caucasian males. The Home Office said it “took steps on the findings”.

“This raises the issue of whether facial recognition only becomes effective if users tolerate discrimination in ethnicity and sex. Operational ease is a poor argument for overriding fundamental rights.”

Known Issue

Internal documents reveal that this bias has been known about for more than a year. Furthermore, law enforcement lobbied to reverse an initial decision that was designed to address the problem.

Senior officers were notified of the algorithmic discrimination in late 2024. The government-ordered laboratory study concluded the system was had a higher probability to produce incorrect matches for images depicting females, individuals of Black ethnicity, and those aged 40 and under.

A Policy U-Turn

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

However, this decision was reversed the following month following complaints from police that the modified technology was generating a lower number of “useful lines of inquiry”. Internal records indicate the higher threshold reduced the number of searches that yielded possible identifications from over half to a just 14%.

Profound Inequalities

Although the Home Office and NPCC declined to specify what setting is now in operation, the latest independent review discovered the system could generate incorrect matches for women of Black heritage nearly a hundred times more frequently than for white women at certain settings.

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

Balancing Utility and Fairness

Outlining the impact of the temporary raise to the system's accuracy setting, the NPCC documents note: “The change significantly reduces the effect of discrimination across protected characteristics of ethnicity, age and gender but had a substantially detrimental effect on operational effectiveness”. The papers further note that police units complained that “a once effective tactic now delivered results of limited benefit”.

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 the relevant minister has labeled the technology as the “biggest breakthrough 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, commented: “We observed scant discussion in race action plan meetings of the facial recognition rollout despite clear relevance with the strategy's goals.

“These revelations demonstrate yet again that the pledges to combat discrimination the police has undertaken through the equality initiative are not being translated into broader operations. Our reports have cautioned that new technologies are being implemented in a context where ethnic inequalities, weak scrutiny and poor data collection already persist.

“All deployment of this technology must adhere to rigorous official guidelines, be subject to external review, and demonstrate it diminishes rather than compounds racial disparity.”

Home Office Response

A Home Office spokesperson said: “We treat the findings of the study with utmost gravity and we have implemented changes. A new algorithm has been independently tested and acquired, which has demonstrated no measurable discrimination. It will be trialled in the coming months and will be subject to further assessment.

“Our priority is protecting the public. This revolutionary tool will support police to apprehend and prosecute offenders. There is human involvement in each stage of the procedure and no arrest or charge would be taken without trained officers meticulously examining the output.”