🔗 Share this article

Law enforcement agencies across the United Kingdom effectively campaigned to use a face scanning system known to be discriminatory against women, youths, and members of ethnic minority groups, after complaining that a less biased version produced fewer potential suspects.

The Technology in Practice

UK forces utilize the police national database (PND) to carry out searches using historical face recognition. This procedure involves comparing a reference photograph of a person of interest against a database of more than 19 million mugshots to identify possible hits.

Admitted Bias

The UK interior ministry conceded last week that the technology was flawed. This admission followed a review by the government's National Physical Laboratory determined it incorrectly matched people of Black and Asian heritage and women at much greater frequency than Caucasian males. The ministry stated it “took steps on the findings”.

“This raises the issue of whether facial recognition only becomes effective if users accept biases in race and gender. Convenience is a poor argument for disregarding basic freedoms.”

Known Issue

Internal documents reveal that this discriminatory flaw has been recognized for more than a year. Furthermore, police forces argued to overturn an initial decision that was intended 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 suggest false positives for photos of females, individuals of Black ethnicity, and those aged 40 and under.

A Reversed Decision

In response, the National Police Chiefs’ Council (NPCC) mandated that the accuracy setting required for possible hits be increased to a level where the bias was greatly diminished.

However, this decision was overturned the next month after forces complained that the adjusted system was generating a lower number of “useful lines of inquiry”. NPCC documents indicate the stricter setting cut the number of searches that yielded possible identifications from 56% to a mere 14%.

Severe Disparities

Although the Home Office and NPCC declined to specify what threshold is now in operation, the latest independent review discovered the system could produce incorrect matches for women of Black heritage almost 100 times more often than for Caucasian women at certain settings.

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

Balancing Utility and Fairness

Describing the effect of the temporary raise to the system's accuracy setting, the NPCC documents state: “The change greatly lessens the impact of discrimination across protected characteristics of race, generation and gender but had a substantially detrimental effect on police efficiency”. The papers add that police units complained that “a once effective tactic now delivered results of questionable value”.

Broader Rollout Plans

Meanwhile, the UK administration has opened 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 tool as the “biggest breakthrough since DNA matching”.

Expert and Oversight Concerns

The chair of a police oversight board, head of the advisory panel for the national policing equality strategy, said: “There was scant consideration in race action plan meetings of the technology deployment despite obvious cross-over with the strategy's goals.

“These revelations demonstrate yet again that the anti-racism commitments policing has undertaken through the equality initiative are not being translated into broader operations. Our reports have cautioned that new technologies are being rolled out in a context where racial disparities, inadequate oversight and poor data collection continue to exist.

“All deployment of facial recognition must meet strict national standards, be subject to external review, and demonstrate it diminishes rather than exacerbates ethnic bias.”

Official Statement

A government representative stated: “The Home Office treat the conclusions of the report seriously and we have implemented changes. A new algorithm has been independently tested and procured, which has demonstrated no measurable discrimination. It will be tested early next year and will be undergo further assessment.

“Our priority is protecting the public. This revolutionary tool will support officers to apprehend and prosecute offenders. There is human involvement in each stage of the process and no further action would be taken without trained officers meticulously examining the results.”