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Law enforcement agencies across the United Kingdom successfully lobbied to use a face scanning system known to be biased against females, young people, and members of ethnic minority groups, after complaining that a more accurate version produced a reduced number of potential suspects.

The Technology in Practice

British police use the police national database (PND) to carry out searches using historical face recognition. This process involves matching a reference photograph of a suspect against a database of over 19 million mugshots to identify possible hits.

Acknowledged Discrimination

The Home Office conceded last week that the technology 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 much greater frequency than Caucasian males. The ministry stated it “had acted on the findings”.

“It prompts the question of whether facial recognition only becomes effective if users accept discrimination in race and gender. Operational ease is a weak argument for overriding basic freedoms.”

Long-Standing Problem

Internal documents reveal that this bias has been recognized for over twelve months. Furthermore, law enforcement argued to overturn an initial decision that was designed to address the problem.

Senior officers were notified of the system's bias in late 2024. The government-ordered NPL review found the system was had a higher probability to suggest incorrect matches for photos of women, individuals of Black ethnicity, and those under 40 years old.

A Reversed Decision

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

However, this decision was overturned the following month after forces complained that the adjusted system was producing a lower number of “investigative leads”. Internal records indicate the stricter setting reduced the proportion of searches that yielded potential matches from 56% to a mere under 15%.

Profound Inequalities

Although the authorities refused to say what setting is currently used, the recent independent review found the system could produce incorrect matches for Black women nearly a hundred times more frequently than for white women at certain settings.

The Home Office stated on these results: “Our evaluation found that in a limited set of circumstances the algorithm is has a greater tendency to incorrectly include some population segments in its search results.”

Balancing Utility and Fairness

Outlining the impact of the temporary raise to the system's accuracy setting, the police records state: “The change significantly reduces the impact of discrimination across legally safeguarded attributes of ethnicity, age and sex but had a substantially detrimental effect on operational effectiveness”. The papers add that forces complained that “a once effective tactic returned outcomes of limited benefit”.

Broader Rollout Plans

Meanwhile, the UK administration has launched a ten-week consultation on its proposals to widen the use of biometric scanning systems. The minister for police the relevant minister has labeled the tool as the “biggest breakthrough since genetic fingerprinting”.

Criticism from Advisors and Monitors

The chair of a police oversight board, head of the advisory panel for the national policing equality strategy, commented: “There was scant consideration through equality strategy sessions of the facial recognition rollout even with clear relevance with the strategy's goals.

“These revelations demonstrate once again that the pledges to combat discrimination policing has made via the race action plan are failing to be integrated into broader operations. Our reports have cautioned that new technologies are being rolled out in a context where ethnic inequalities, inadequate oversight and faulty information gathering continue to exist.

“Any use of facial recognition must meet rigorous official guidelines, be independently scrutinised, and prove it reduces rather than exacerbates racial disparity.”

Home Office Response

A Home Office spokesperson said: “The Home Office treat the findings of the report seriously and we have implemented changes. A updated software has been externally evaluated and acquired, which has demonstrated no measurable discrimination. It will be tested in the coming months and will be subject to evaluation.

“The foremost aim is protecting the public. This revolutionary tool will support police to apprehend and prosecute offenders. There is officer review in each stage of the process and no further action would be taken without specialist personnel meticulously examining the results.”