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Police forces across the United Kingdom successfully lobbied to deploy a facial recognition system acknowledged as biased against females, young people, and members of minority ethnic backgrounds, following complaints that a less biased version generated a reduced number of potential suspects.

The Technology in Practice

UK forces utilize the national police database to carry out searches using historical face recognition. This procedure involves matching a reference photograph of a suspect against a repository of more than 19 million custody photos to find possible hits.

Admitted Bias

The Home Office conceded last week that the technology was biased. This admission came after a review by the government's National Physical Laboratory found it incorrectly matched people of Black and Asian heritage and women at much greater frequency than white men. The Home Office stated it “took steps on the findings”.

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

Long-Standing Problem

Official papers show that this bias has been known about for more than a year. Furthermore, law enforcement argued to overturn an earlier ruling that was intended to mitigate the problem.

Police bosses were informed of the algorithmic discrimination in September 2024. The government-ordered NPL review found the system was had a higher probability to suggest false positives for images depicting women, Black people, and those under 40 years old.

A Policy U-Turn

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

However, this decision was overturned the following month following complaints from police that the modified technology was producing a lower number of “investigative leads”. NPCC documents show the stricter setting cut the number of queries resulting in possible identifications from over half to a just under 15%.

Profound Inequalities

Although the Home Office and NPCC declined to specify what setting is currently used, the latest independent review discovered the system could produce incorrect matches for women of Black heritage nearly a hundred times more frequently than for Caucasian women at specific configurations.

The Home Office commented on these findings: “The testing found that in a limited set of circumstances the algorithm is has a greater tendency to incorrectly include some population segments in its match reports.”

Balancing Utility and Fairness

Describing the impact of the brief increase to the system's accuracy setting, the NPCC documents state: “This adjustment greatly lessens the effect of bias across protected characteristics of ethnicity, age and gender but had a significant negative impact on operational effectiveness”. The documents further note that forces argued that “a once effective tactic now delivered results of limited benefit”.

Broader Rollout Plans

Meanwhile, the government has launched a ten-week public review on its plans to widen the use of biometric scanning systems. The minister for police Sarah Jones has labeled the technology as the “biggest breakthrough since DNA matching”.

Expert and Oversight Concerns

The chair of a police oversight board, chair of the advisory panel for the police race action plan, said: “There was very little discussion through equality strategy sessions of the technology deployment even with obvious cross-over with the strategy's goals.

“This disclosure demonstrate once again that the anti-racism commitments policing has made via the equality initiative are not being translated into broader operations. Independent assessments have cautioned that new technologies are being implemented in a landscape where ethnic inequalities, weak scrutiny and faulty information gathering already persist.

“All deployment of facial recognition must adhere to rigorous official guidelines, be subject to external review, and prove it reduces rather than compounds racial disparity.”

Home Office Response

A government representative stated: “The Home Office takes the findings of the study seriously and we have implemented changes. A new algorithm has been externally evaluated and procured, which has no statistically significant bias. It will be tested in the coming months and will be undergo further assessment.

“The foremost aim is ensuring public safety. This revolutionary tool will support police to put criminals and rapists behind bars. There is officer review in every step of the process and no arrest or charge would be pursued without specialist personnel meticulously examining the results.”