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Law enforcement agencies across the United Kingdom effectively campaigned to deploy a facial recognition system acknowledged as biased against women, young people, and members of ethnic minority groups, following complaints that a less biased version generated a reduced number of potential suspects.

How the System Works

British police utilize the national police database to conduct retrospective facial recognition searches. This procedure involves matching a “probe image” of a person of interest against a database of more than 19 million custody photos to identify possible hits.

Acknowledged Discrimination

The UK interior ministry conceded last week that the technology was flawed. This acknowledgment came after a review by the National Physical Laboratory (NPL) found it incorrectly matched people of Black and Asian heritage and females at significantly higher rates than white men. The Home Office stated it “had acted on the findings”.

“It prompts the question of whether this technology only becomes useful if users accept biases in ethnicity and sex. Operational ease is a weak argument for disregarding basic freedoms.”

Long-Standing Problem

Official papers show 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.

Police bosses were informed of the algorithmic discrimination in September 2024. The government-ordered NPL review concluded the system was more likely to produce incorrect matches for photos of women, individuals of Black ethnicity, and those under 40 years old.

A Reversed Decision

In response, the National Police Chiefs’ Council (NPCC) ordered that the confidence threshold required for potential matches be raised to a level where the bias was significantly reduced.

However, this directive was overturned the following month after forces complained that the modified technology was generating fewer “useful lines of inquiry”. Internal records indicate the higher threshold cut the number of queries resulting in potential matches from over half to a just 14%.

Profound Inequalities

Although the Home Office and NPCC refused to say what setting is now in operation, the latest NPL study discovered the system could produce false positives for women of Black heritage almost 100 times more often than for Caucasian women at specific configurations.

The ministry commented on these findings: “Our evaluation found that in a specific scenarios the software is has a greater tendency to incorrectly include some demographic groups in its search results.”

Balancing Utility and Fairness

Outlining the impact of the brief increase to the system's accuracy setting, the NPCC documents note: “The change greatly lessens the effect of discrimination across legally safeguarded attributes of ethnicity, age and gender but had a significant negative impact on operational effectiveness”. The documents add that forces complained that “a previously useful tool returned outcomes of limited benefit”.

Broader Rollout Plans

Meanwhile, the UK administration has opened a ten-week consultation on its plans to expand the use of facial recognition technology. The minister for police the relevant minister has labeled the technology as the “most significant advance since DNA matching”.

Criticism from Advisors and Monitors

The chair of a police oversight board, chair of the independent scrutiny and oversight board for the national policing equality strategy, said: “We observed scant consideration through race action plan meetings of the facial recognition rollout even with clear relevance with the plan’s concerns.

“This disclosure demonstrate yet 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 warned that innovative tools are being implemented in a context where ethnic inequalities, inadequate oversight and poor data collection continue to exist.

“All deployment of this technology 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 conclusions of the study with utmost gravity and we have implemented changes. A updated software has been independently tested and acquired, which has no statistically significant bias. It will be trialled in the coming months and will be subject to evaluation.

“The foremost aim is protecting the public. This gamechanging technology will assist police to put criminals and rapists behind bars. There is human involvement in every step of the process and no arrest or charge would be taken without trained officers carefully reviewing the results.”