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Police forces across the United Kingdom successfully lobbied to deploy a facial recognition system acknowledged as biased against females, youths, and members of ethnic minority groups, after complaining that a more accurate version produced fewer potential suspects.

The Technology in Practice

British police utilize the police national database (PND) to carry out searches using historical face recognition. This process entails comparing a reference photograph of a person of interest against a repository of more than 19 million custody photos to identify possible hits.

Acknowledged Discrimination

The UK interior ministry admitted last week that the technology was biased. This acknowledgment came after a study by the National Physical Laboratory (NPL) determined it incorrectly matched Black and Asian people and women at significantly higher rates than Caucasian males. The Home Office stated it “had acted on the findings”.

“It prompts the question of whether this technology only becomes effective if users accept discrimination in race and gender. Convenience is a poor argument for disregarding fundamental rights.”

Known Issue

Internal documents reveal that this discriminatory flaw has been recognized for over twelve months. Furthermore, law enforcement argued to overturn an initial decision that was intended to mitigate the problem.

Police bosses were informed of the algorithmic discrimination in late 2024. The Home Office-commissioned laboratory study concluded 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 Policy U-Turn

In reaction, the National Police Chiefs’ Council (NPCC) mandated that the confidence threshold required for potential matches be raised to a point where the disparity was significantly reduced.

However, this directive was reversed the next month after forces complained that the modified technology was generating fewer “useful lines of inquiry”. NPCC documents show the higher threshold reduced the number of searches that yielded possible identifications from over half to a mere under 15%.

Severe Disparities

Although the authorities refused to say what threshold is now in operation, the recent NPL study discovered the system could generate false positives for women of Black heritage nearly a hundred times more often than for Caucasian women at certain settings.

The Home Office stated on these findings: “Our evaluation identified that in a specific scenarios the software is has a greater tendency to incorrectly include some demographic groups in its match reports.”

Operational Effectiveness vs. Bias

Outlining the impact of the temporary raise to the system's confidence threshold, the police records state: “The change significantly reduces the impact of bias across protected characteristics of ethnicity, age and gender but had a significant negative impact on police efficiency”. The papers add that police units complained that “a once effective tactic now delivered outcomes of questionable value”.

Wider Implementation Proposals

Meanwhile, the UK administration has launched a ten-week public review on its proposals to expand the use of facial recognition technology. The minister for police Sarah Jones has described the technology as the “most significant advance since genetic fingerprinting”.

Expert and Oversight Concerns

The chair of a police oversight board, head of the independent scrutiny and oversight board for the national policing equality strategy, commented: “There was very little consideration through equality strategy sessions of the technology deployment despite clear relevance with the plan’s concerns.

“These revelations demonstrate once again that the pledges to combat discrimination the police has undertaken through the equality initiative are not being translated into wider practice. Independent assessments have cautioned that new technologies are being rolled out in a landscape where ethnic inequalities, inadequate oversight and faulty information gathering already persist.

“All deployment of facial recognition must adhere to strict national standards, be independently scrutinised, and prove it diminishes rather than exacerbates racial disparity.”

Official Statement

A government representative stated: “The Home Office takes the conclusions of the study with utmost gravity and we have already taken action. A new algorithm has been externally evaluated and acquired, which has no statistically significant bias. It will be tested early next year and will be subject to evaluation.

“The foremost aim is protecting the public. This gamechanging technology will support police to apprehend and prosecute offenders. There is officer review in every step of the process and no arrest or charge would be pursued without specialist personnel carefully reviewing the results.”