🔗 Share this article

Police forces across the United Kingdom effectively campaigned to deploy a face scanning system known to be discriminatory against females, youths, and members of ethnic minority groups, after complaining that a more accurate 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 entails comparing a reference photograph of a person of interest against a database of over 19 million mugshots to identify possible hits.

Admitted Bias

The Home Office admitted last week that the technology was biased. This acknowledgment followed a study by the National Physical Laboratory (NPL) determined it incorrectly matched Black and Asian people and females at significantly higher rates than Caucasian males. The Home Office stated it “took steps on the findings”.

“It prompts the issue of whether this technology only becomes effective if users accept discrimination in race and gender. Operational ease is a weak argument for disregarding fundamental rights.”

Known Issue

Internal documents reveal that this discriminatory flaw has been recognized for over twelve months. Furthermore, law enforcement argued to overturn an initial decision that was designed to mitigate the problem.

Senior officers were notified of the system's bias in late 2024. The Home Office-commissioned laboratory study concluded the system was had a higher probability to suggest incorrect matches for photos of women, individuals of Black ethnicity, and those under 40 years old.

A Reversed Decision

In response, the national police leadership body ordered that the accuracy setting required for possible hits be increased to a point where the disparity was greatly diminished.

However, this directive was overturned the following month following complaints from police that the adjusted system was generating fewer “useful lines of inquiry”. NPCC documents show the higher threshold reduced the proportion of searches that yielded possible identifications from 56% to a mere 14%.

Profound Inequalities

Although the authorities refused to say what threshold is currently used, the recent NPL study discovered the system could produce incorrect matches for Black women almost 100 times more frequently than for white women at certain settings.

The ministry commented on these results: “Our evaluation identified that in a specific scenarios the software is has a greater tendency to incorrectly include some population segments in its match reports.”

Operational Effectiveness vs. Bias

Describing the effect of the temporary raise to the system's confidence threshold, the NPCC documents state: “This adjustment significantly reduces the effect of discrimination across legally safeguarded attributes of ethnicity, generation and sex but had a substantially detrimental effect on operational effectiveness”. The papers add that forces complained that “a once effective tactic now delivered results of questionable value”.

Broader Rollout Plans

Meanwhile, the UK administration has launched a ten-week public review on its proposals to widen the use of facial recognition technology. Policing minister Sarah Jones has labeled the tool as the “most significant advance since genetic fingerprinting”.

Criticism from Advisors and Monitors

Abimbola Johnson, head of the advisory panel for the national policing equality strategy, said: “There was very little discussion in race action plan meetings of the technology deployment even with clear relevance with the strategy's goals.

“These revelations demonstrate yet again that the anti-racism commitments the police has made through the equality initiative are not being translated into broader operations. Independent assessments have cautioned that innovative tools are being implemented in a context where racial disparities, weak scrutiny and poor data collection already persist.

“Any use of facial recognition must meet rigorous official guidelines, be independently scrutinised, and demonstrate it diminishes rather than exacerbates racial disparity.”

Official Statement

A government representative stated: “We treat the findings of the report seriously and we have already taken action. A new algorithm has been independently tested and acquired, which has demonstrated no measurable discrimination. It will be trialled in the coming months and will be undergo evaluation.

“The foremost aim is protecting the public. This gamechanging technology will support officers to put criminals and rapists behind bars. There is officer review in every step of the procedure and no arrest or charge would be taken without specialist personnel carefully reviewing the results.”