British Law Enforcement Agencies Lobbied to Use Discriminatory Face Scanning Systems

Police forces across the UK effectively campaigned to deploy a facial recognition system known to be biased against women, young people, and individuals from ethnic minority groups, following complaints that a less biased version produced a reduced number of potential suspects.

How the System Works

British police use 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 database of over 19 million custody photos to identify possible hits.

Acknowledged Discrimination

The Home Office admitted last week that the system was flawed. This acknowledgment followed a review by the government's National Physical Laboratory found it misidentified Black and Asian people and women at much greater frequency than white men. The ministry stated it “had acted on the findings”.

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

Long-Standing Problem

Official papers show that this discriminatory flaw has been known about for over twelve months. Furthermore, law enforcement argued to overturn an initial decision that was intended to address the problem.

Police bosses were notified of the system's bias in September 2024. The Home Office-commissioned NPL review found the system was had a higher probability to produce false positives for photos of females, individuals of Black ethnicity, and those aged 40 and under.

A Reversed Decision

In reaction, the national police leadership body ordered that the confidence threshold required for potential matches be increased to a point where the bias was significantly reduced.

However, this decision was overturned the following month following complaints from police that the modified technology was producing a lower number of “investigative leads”. NPCC documents indicate the higher threshold cut the number of searches that yielded possible identifications from 56% to a just 14%.

Profound Inequalities

Although the authorities declined to specify what setting is now in operation, the recent NPL study found the system could generate incorrect matches for women of Black heritage almost 100 times more often than for white women at specific configurations.

The Home Office stated on these findings: “The testing identified that in a specific scenarios the algorithm is more likely to incorrectly include some population segments in its match reports.”

Operational Effectiveness vs. Bias

Describing the impact of the temporary raise to the system's accuracy setting, the police records note: “This adjustment greatly lessens the impact of bias across legally safeguarded attributes of ethnicity, generation and gender but had a significant negative impact on operational effectiveness”. The papers further note that police units argued that “a previously useful tool returned outcomes of limited benefit”.

Broader Rollout Plans

Meanwhile, the government has launched a ten-week consultation on its plans to expand the use of facial recognition technology. Policing minister the relevant minister has described the tool as the “biggest breakthrough since genetic fingerprinting”.

Criticism from Advisors and Monitors

Abimbola Johnson, chair of the independent scrutiny and oversight board for the police race action plan, commented: “We observed very little consideration in race action plan meetings of the technology deployment even with clear relevance with the plan’s concerns.

“This disclosure show once again that the anti-racism commitments policing has made through the race action plan are failing to be integrated into broader operations. Independent assessments have warned that innovative tools are being implemented in a landscape where racial disparities, weak scrutiny and faulty information gathering continue to exist.

“All deployment of this technology must adhere to rigorous official guidelines, be independently scrutinised, and prove it diminishes rather than compounds ethnic bias.”

Official Statement

A government representative stated: “The Home Office treat the findings of the report with utmost gravity and we have already taken action. A new algorithm 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.

“Our priority is ensuring public safety. This revolutionary tool will assist police to apprehend and prosecute offenders. There is human involvement in each stage of the procedure and no arrest or charge would be taken without specialist personnel carefully reviewing the results.”