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Police forces across the UK effectively campaigned to use a facial recognition system acknowledged as discriminatory against females, young people, and members of minority ethnic backgrounds, after complaining that a more accurate version generated a reduced number of investigative leads.

How the System Works

British police utilize the national police database to carry out searches using historical face recognition. This process entails matching a “probe image” of a suspect against a repository of over 19 million mugshots to identify potential matches.

Acknowledged Discrimination

The UK interior ministry admitted last week that the technology was flawed. This acknowledgment came after a review by the government's National Physical Laboratory determined it misidentified Black and Asian people and women at significantly higher rates than white men. The ministry said 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 basic freedoms.”

Known Issue

Official papers show that this bias has been recognized for over twelve months. Furthermore, police forces argued to overturn an earlier ruling that was designed to mitigate the problem.

Senior officers were informed of the system's bias in September 2024. The government-ordered NPL review found the system was had a higher probability to suggest incorrect matches for images depicting females, Black people, and those aged 40 and under.

A Policy U-Turn

In reaction, the National Police Chiefs’ Council (NPCC) mandated that the accuracy setting required for potential matches be raised to a level where the bias was significantly reduced.

However, this decision was reversed the following month following complaints from police that the modified technology was producing fewer “investigative leads”. NPCC documents show the stricter setting reduced the proportion of searches resulting in potential matches from over half to a just under 15%.

Profound Inequalities

Although the Home Office and NPCC declined to specify what threshold is currently used, the latest independent review discovered the system could generate false positives for Black women nearly a hundred times more often than for Caucasian women at certain settings.

The Home Office commented on these results: “The testing found that in a specific scenarios the software is more likely to incorrectly include some demographic groups in its search results.”

Operational Effectiveness vs. Bias

Outlining the effect of the brief increase to the system's accuracy setting, the police records state: “The change significantly reduces the impact of discrimination across protected characteristics of race, generation and sex but had a significant negative impact on police efficiency”. The documents add that forces argued that “a once effective tactic returned outcomes of questionable value”.

Wider Implementation Proposals

Meanwhile, the government has opened a ten-week public review on its plans to expand the use of biometric scanning systems. The minister for police Sarah Jones has described the tool as the “biggest breakthrough since genetic fingerprinting”.

Expert and Oversight Concerns

The chair of a police oversight board, head of the advisory panel for the police race action plan, commented: “There was very little consideration in equality strategy sessions of the technology deployment even with clear relevance with the plan’s concerns.

“These revelations demonstrate once again that the anti-racism commitments the police has undertaken through the equality initiative are failing to be integrated into wider practice. Independent assessments have warned that innovative tools are being rolled out in a context where ethnic inequalities, inadequate oversight and faulty information gathering already persist.

“All deployment of this technology must meet rigorous official guidelines, be subject to external review, and prove it reduces rather than exacerbates ethnic bias.”

Official Statement

A Home Office spokesperson said: “We takes the findings of the report seriously and we have already taken action. A updated software has been independently tested and procured, which has no statistically significant bias. It will be trialled early next year and will be subject to further assessment.

“The foremost aim is protecting the public. This revolutionary tool will assist officers to put criminals and rapists behind bars. There is officer review in every step of the process and no further action would be pursued without trained officers carefully reviewing the results.”