🔗 Share this article

Law enforcement agencies across the United Kingdom effectively campaigned to deploy a face scanning system known to be biased against females, youths, and members of minority ethnic backgrounds, following complaints that a less biased version generated fewer potential suspects.

The Technology in Practice

British police utilize the national police database to carry out searches using historical face recognition. This procedure involves comparing a reference photograph of a suspect against a database of over 19 million mugshots to find possible hits.

Admitted Bias

The UK interior ministry admitted last week that the system was biased. This admission followed a study by the government's National Physical Laboratory found it incorrectly matched Black and Asian people and women at significantly higher rates than white men. The Home Office said it “took steps on the findings”.

“This raises the question of whether this technology only becomes useful if users tolerate discrimination in ethnicity and sex. Operational ease is a poor argument for overriding fundamental rights.”

Long-Standing Problem

Internal documents show that this discriminatory flaw has been recognized for over twelve months. Furthermore, police forces 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 produce false positives for images depicting 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 accuracy setting required for possible hits be raised to a point where the disparity was significantly reduced.

However, this decision was reversed the following month after forces complained that the modified technology was generating fewer “useful lines of inquiry”. Internal records show the higher threshold cut the proportion of queries that yielded possible identifications from 56% to a just 14%.

Severe Disparities

Although the authorities refused to say what setting is now in operation, the latest independent review discovered the system could produce false positives for Black women almost 100 times more often than for Caucasian women at specific configurations.

The ministry commented on these results: “Our evaluation identified that in a limited set of circumstances the algorithm is has a greater tendency to wrongly flag some demographic groups in its search results.”

Balancing Utility and Fairness

Describing the impact of the temporary raise to the system's accuracy setting, the NPCC documents state: “This adjustment greatly lessens the impact of discrimination across protected characteristics of race, age and gender but had a substantially detrimental effect on police efficiency”. The papers add that forces argued that “a previously useful tool now delivered outcomes of limited benefit”.

Wider Implementation Proposals

Meanwhile, the UK administration has launched a two-and-a-half-month public review on its proposals to expand the use of biometric scanning systems. Policing minister the relevant minister has labeled the tool as the “most significant advance since DNA matching”.

Expert and Oversight Concerns

Abimbola Johnson, chair of the independent scrutiny and oversight board for the national policing equality strategy, said: “We observed scant discussion through race action plan meetings of the facial recognition rollout despite obvious cross-over with the strategy's goals.

“This disclosure demonstrate yet again that the pledges to combat discrimination the police has undertaken through the race action plan are not being translated into broader operations. Independent assessments have cautioned that innovative tools are being implemented in a landscape where ethnic inequalities, weak scrutiny and poor data collection already persist.

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

Home Office Response

A government representative stated: “We treat the findings of the study seriously and we have implemented changes. A new algorithm has been externally evaluated and acquired, which has demonstrated no measurable discrimination. It will be trialled in the coming months and will be subject to further assessment.

“The foremost aim is protecting the public. This revolutionary tool will support police to put criminals and rapists behind bars. There is human involvement in each stage of the process and no arrest or charge would be pursued without specialist personnel carefully reviewing the results.”