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Police forces across the UK effectively campaigned to deploy a face scanning system known to be discriminatory against females, youths, and individuals from ethnic minority groups, after complaining that a more accurate version generated fewer investigative leads.

The Technology in Practice

UK forces utilize the police national database (PND) to conduct searches using historical face recognition. This procedure involves matching 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 Home Office conceded last week that the technology was biased. This admission followed a study by the government's National Physical Laboratory determined it incorrectly matched people of Black and Asian heritage and females at significantly higher rates than white men. The Home Office said it “had acted on the findings”.

“It prompts the question of whether facial recognition only becomes effective if users accept biases in ethnicity and gender. Operational ease is a weak argument for overriding fundamental rights.”

Known Issue

Official papers show that this discriminatory flaw has been recognized for over twelve months. Furthermore, police forces argued to overturn an initial decision that was designed to address the problem.

Police bosses were notified of the system's bias in September 2024. The government-ordered laboratory study found the system was had a higher probability to suggest incorrect matches for photos of females, individuals of Black ethnicity, and those aged 40 and under.

A Policy U-Turn

In reaction, the national police leadership body ordered that the confidence threshold required for possible hits be raised to a level where the bias was greatly diminished.

However, this decision was overturned the next month after forces complained that the modified technology was producing a lower number of “investigative leads”. NPCC documents show the higher threshold reduced the number of queries that yielded possible identifications from 56% to a mere under 15%.

Profound Inequalities

Although the Home Office and NPCC declined to specify what threshold is currently used, the latest NPL study found the system could produce incorrect matches for Black women nearly a hundred times more often than for Caucasian women at specific configurations.

The Home Office commented on these findings: “Our evaluation found that in a limited set of circumstances the software is has a greater tendency to wrongly flag some population segments in its match reports.”

Balancing Utility and Fairness

Outlining the effect of the temporary raise to the system's confidence threshold, the NPCC documents state: “This adjustment greatly lessens the impact of discrimination across legally safeguarded attributes of race, generation and gender but had a substantially detrimental effect on police efficiency”. The papers further note that forces complained that “a once effective tactic returned results of questionable value”.

Wider Implementation Proposals

Meanwhile, the UK administration has launched a ten-week consultation on its plans to widen the use of facial recognition technology. The minister for police Sarah Jones has labeled the technology as the “most significant advance since genetic fingerprinting”.

Expert and Oversight Concerns

Abimbola Johnson, chair of the advisory panel for the national policing equality strategy, commented: “There was scant consideration through equality strategy sessions of the technology deployment even with obvious cross-over with the strategy's goals.

“This disclosure show once again that the anti-racism commitments the police has made through the equality initiative are failing to be integrated into wider practice. Independent assessments have warned that new technologies are being implemented in a context where ethnic inequalities, inadequate oversight and faulty information gathering already persist.

“Any use of this technology must meet rigorous official guidelines, be subject to external review, and prove it diminishes rather than compounds racial disparity.”

Official Statement

A government representative stated: “The Home Office treat the conclusions of the study with utmost gravity and we have implemented changes. A updated software has been independently tested and acquired, which has demonstrated no measurable discrimination. It will be tested in the coming months and will be undergo evaluation.

“The foremost aim is protecting the public. This revolutionary tool will assist officers to apprehend and prosecute offenders. There is officer review in each stage of the procedure and no arrest or charge would be taken without specialist personnel meticulously examining the output.”