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Law enforcement agencies across the UK effectively campaigned to deploy a face scanning system known to be discriminatory against women, youths, and individuals from minority ethnic backgrounds, after complaining that a less biased version generated a reduced number of potential suspects.

How the System Works

UK forces utilize the national police database to carry out searches using historical face recognition. This process involves matching a “probe image” of a person of interest against a database of more than 19 million mugshots to find potential matches.

Admitted Bias

The UK interior ministry conceded last week that the system was biased. This admission came after a study by the government's National Physical Laboratory determined it misidentified people of Black and Asian heritage and women at much greater frequency than white men. The ministry said it “took steps on the findings”.

“It prompts the issue of whether facial recognition only becomes effective if users tolerate biases in ethnicity and gender. Convenience is a weak argument for disregarding basic freedoms.”

Known Issue

Official papers reveal that this discriminatory flaw has been recognized for over twelve months. Furthermore, police forces lobbied to reverse an initial decision that was designed to mitigate the problem.

Senior officers were notified of the system's bias in late 2024. The government-ordered NPL review found the system was more likely to produce incorrect matches for images depicting women, individuals of Black ethnicity, and those aged 40 and under.

A Reversed Decision

In reaction, the national police leadership body mandated that the accuracy setting required for potential matches be raised to a point where the disparity was greatly diminished.

However, this directive was overturned the next month after forces complained that the adjusted system was producing fewer “investigative leads”. NPCC documents show the stricter setting cut the proportion of queries resulting in possible identifications from 56% to a just 14%.

Profound Inequalities

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

The Home Office commented on these results: “Our evaluation identified that in a limited set of circumstances the algorithm is has a greater tendency to incorrectly include some demographic groups in its match reports.”

Operational Effectiveness vs. Bias

Describing the effect of the brief increase to the system's confidence threshold, the police records state: “This adjustment significantly reduces the impact of bias across legally safeguarded attributes of race, age and sex but had a significant negative impact on police efficiency”. The documents further note that police units argued that “a once effective tactic returned outcomes of questionable value”.

Wider Implementation Proposals

Meanwhile, the government has launched a two-and-a-half-month public review on its plans to expand the use of facial recognition technology. Policing minister Sarah Jones has described the technology as the “most significant advance since DNA matching”.

Criticism from Advisors and Monitors

Abimbola Johnson, chair of the independent scrutiny and oversight board for the police race action plan, said: “There was scant discussion in equality strategy sessions of the facial recognition rollout despite obvious cross-over with the plan’s concerns.

“This disclosure show yet again that the anti-racism commitments policing has made through the race action plan are failing to be integrated into wider practice. Independent assessments have warned that new technologies are being implemented in a context where ethnic inequalities, weak scrutiny and faulty information gathering already persist.

“Any use of this technology must adhere to rigorous official guidelines, be independently scrutinised, and prove it reduces rather than exacerbates ethnic bias.”

Official Statement

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

“The foremost aim is ensuring public safety. This gamechanging technology will support officers to apprehend and prosecute offenders. There is officer review in each stage of the procedure and no further action would be taken without trained officers meticulously examining the output.”