British Law Enforcement Agencies Lobbied to Employ Discriminatory Face Scanning Systems

Law enforcement agencies across the United Kingdom effectively campaigned to use a facial recognition system known to be biased against women, young people, and members of minority ethnic backgrounds, after complaining that a less biased version generated a reduced number of investigative leads.

The Technology in Practice

British police utilize the police national database (PND) to carry out searches using historical face recognition. This procedure involves matching a reference photograph of a person of interest against a repository of over 19 million mugshots to identify possible hits.

Admitted Bias

The Home Office conceded last week that the system was flawed. This admission came after a study by the government's National Physical Laboratory found it misidentified Black and Asian people and women at much greater frequency than Caucasian males. The ministry stated it “had acted on the findings”.

“This raises the issue of whether facial recognition only becomes effective if users tolerate biases in ethnicity and gender. Operational ease is a weak argument for disregarding fundamental rights.”

Long-Standing Problem

Internal documents show that this discriminatory flaw has been known about for over twelve months. Furthermore, law enforcement lobbied to reverse an earlier ruling that was designed to mitigate the problem.

Senior officers were notified of the system's bias in September 2024. The Home Office-commissioned laboratory study found the system was more likely to produce false positives for photos of women, individuals of Black ethnicity, and those aged 40 and under.

A Reversed Decision

In reaction, the National Police Chiefs’ Council (NPCC) ordered that the confidence threshold required for potential matches 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”. Internal records show the stricter setting reduced the number of queries that yielded possible identifications from 56% to a mere under 15%.

Severe Disparities

Although the authorities declined to specify what threshold is currently used, the recent independent review discovered the system could generate incorrect matches for Black women nearly a hundred times more often than for white women at specific configurations.

The Home Office commented on these results: “The testing found that in a specific scenarios the software is more likely to wrongly flag some demographic groups in its match reports.”

Operational Effectiveness vs. Bias

Outlining the effect of the brief increase to the system's confidence threshold, the NPCC documents state: “The change significantly reduces the impact of discrimination across protected characteristics of race, age and sex but had a substantially detrimental effect on operational effectiveness”. The papers further note that forces argued that “a previously useful tool returned outcomes of questionable value”.

Broader Rollout Plans

Meanwhile, the government has launched a two-and-a-half-month public review on its proposals to widen the use of biometric scanning systems. Policing minister Sarah Jones has labeled the tool as the “most significant advance since genetic fingerprinting”.

Criticism from Advisors and Monitors

The chair of a police oversight board, chair of the independent scrutiny and oversight board for the police race action plan, said: “We observed scant consideration through race action plan meetings of the technology deployment even with clear relevance with the plan’s concerns.

“These revelations show once again that the anti-racism commitments the police has made via the race action plan are failing to be integrated into wider practice. Our reports have warned that innovative tools are being implemented in a landscape 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 compounds racial disparity.”

Home Office Response

A government representative said: “The Home Office takes the conclusions of the report with utmost gravity and we have implemented changes. A updated software has been externally evaluated and acquired, which has demonstrated no measurable discrimination. It will be tested in the coming months and will be undergo evaluation.

“Our priority is ensuring public safety. This gamechanging technology will support police to apprehend and prosecute offenders. There is officer review in each stage of the process and no further action would be taken without trained officers carefully reviewing the output.”