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Law enforcement agencies across the United Kingdom effectively campaigned to use a facial recognition system acknowledged as discriminatory against women, youths, and individuals from ethnic minority groups, following complaints that a more accurate version produced fewer investigative leads.

The Technology in Practice

British police utilize the national police database to carry out searches using historical face recognition. This process involves comparing a reference photograph of a suspect against a repository of over 19 million custody photos to find possible hits.

Acknowledged Discrimination

The Home Office admitted last week that the technology was biased. This acknowledgment came after a review by the National Physical Laboratory (NPL) found it misidentified people of Black and Asian heritage and women at significantly higher rates than Caucasian males. The ministry stated it “took steps on the findings”.

“This raises the issue of whether this technology only becomes effective if users accept discrimination in ethnicity and gender. Operational ease is a poor argument for disregarding basic freedoms.”

Known Issue

Official papers show that this bias has been known about for over twelve months. Furthermore, law enforcement argued to overturn an earlier ruling that was designed to mitigate the problem.

Police bosses were notified of the algorithmic discrimination in late 2024. The government-ordered NPL review found the system was more likely to produce incorrect matches for images depicting females, Black people, and those aged 40 and under.

A Policy U-Turn

In response, the National Police Chiefs’ Council (NPCC) ordered that the confidence threshold required for potential matches be increased to a point where the bias was greatly diminished.

However, this directive was reversed the next month following complaints from police that the adjusted system was producing fewer “useful lines of inquiry”. Internal records indicate the higher threshold reduced the proportion of queries that yielded possible identifications from 56% to a mere under 15%.

Severe Disparities

Although the authorities refused to say what setting is now in operation, the recent NPL study discovered the system could generate false positives for Black women almost 100 times more often than for white women at specific configurations.

The ministry stated on these findings: “The testing found that in a limited set of circumstances the software is more likely to wrongly flag some demographic groups in its match reports.”

Balancing Utility and Fairness

Outlining the effect of the brief increase to the system's confidence threshold, the police records note: “The change greatly lessens the effect of discrimination across legally safeguarded attributes of ethnicity, generation and sex but had a significant negative impact on police efficiency”. The documents further note that police units argued that “a once effective tactic now delivered outcomes of questionable value”.

Broader Rollout Plans

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

Criticism from Advisors and Monitors

Abimbola Johnson, head of the advisory panel for the national policing equality strategy, said: “There was very little consideration through equality strategy sessions of the facial recognition rollout despite obvious cross-over with the strategy's goals.

“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 wider practice. Independent assessments have cautioned that innovative tools are being implemented in a landscape where racial disparities, inadequate oversight and faulty information gathering already persist.

“Any use of facial recognition must meet rigorous official guidelines, be subject to external review, and prove it diminishes rather than compounds ethnic bias.”

Official Statement

A Home Office spokesperson said: “We treat the conclusions of the study with utmost gravity and we have implemented changes. A new algorithm has been independently tested and procured, which has demonstrated no measurable discrimination. It will be trialled early next year and will be undergo further assessment.

“The foremost aim is protecting the public. This revolutionary tool will assist officers to put criminals and rapists behind bars. There is human involvement in each stage of the process and no further action would be taken without specialist personnel carefully reviewing the results.”