UK Law Enforcement Agencies Lobbied to Use Discriminatory Facial Recognition Technology

Law enforcement agencies across the UK successfully lobbied to use a face scanning system known to be biased against females, young people, and members of ethnic minority groups, after complaining that a more accurate version generated fewer investigative leads.

The Technology in Practice

British police use the national police database to conduct searches using historical face recognition. This process involves comparing a “probe image” of a person of interest against a database of over 19 million custody photos to identify possible hits.

Acknowledged Discrimination

The UK interior ministry conceded last week that the technology was biased. This acknowledgment came after a review by the National Physical Laboratory (NPL) found it incorrectly matched Black and Asian people and females at much greater frequency than Caucasian males. The Home Office stated it “had acted on the findings”.

“It prompts the question of whether this technology only becomes effective if users tolerate biases in race and gender. Convenience is a poor argument for disregarding fundamental rights.”

Known Issue

Official papers show that this discriminatory flaw has been recognized for over twelve months. Furthermore, law enforcement lobbied to reverse an initial decision that was designed to mitigate the problem.

Senior officers were informed of the system's bias in September 2024. The Home Office-commissioned NPL review concluded the system was more likely to produce incorrect matches for images depicting women, individuals of Black ethnicity, and those aged 40 and under.

A Reversed Decision

In reaction, the national police leadership body mandated that the accuracy setting required for potential matches be raised to a level where the bias was significantly reduced.

However, this directive was reversed the following month after forces complained that the adjusted system was producing a lower number of “useful lines of inquiry”. Internal records indicate the stricter setting reduced the number of queries that yielded potential matches from 56% to a mere under 15%.

Profound Inequalities

Although the authorities refused to say what threshold is now in operation, the recent NPL study found the system could generate false positives for Black women almost 100 times more frequently than for Caucasian women at specific configurations.

The ministry commented on these findings: “The testing found that in a limited set of circumstances the software is more likely to wrongly flag some demographic groups in its search results.”

Operational Effectiveness vs. Bias

Describing the impact of the brief increase to the system's accuracy setting, the police records state: “The change greatly lessens the impact of bias across protected characteristics of ethnicity, age and gender but had a significant negative impact on operational effectiveness”. The documents further note that forces argued that “a previously useful tool now delivered results of questionable value”.

Wider Implementation Proposals

Meanwhile, the government has opened a two-and-a-half-month consultation on its proposals to widen the use of biometric scanning systems. Policing minister the relevant minister has labeled the technology as the “biggest breakthrough since genetic fingerprinting”.

Criticism from Advisors and Monitors

Abimbola Johnson, head of the independent scrutiny and oversight board for the police race action plan, commented: “There was scant consideration through equality strategy sessions of the technology deployment even with clear relevance with the strategy's goals.

“This disclosure demonstrate yet again that the pledges to combat discrimination policing has made through the race action plan are not being translated into wider practice. Our reports have cautioned that new technologies are being implemented in a context where ethnic inequalities, weak scrutiny and faulty information gathering already persist.

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

Official Statement

A government representative stated: “The Home Office takes the conclusions of the report with utmost gravity and we have already taken action. A new algorithm has been independently tested and acquired, which has no statistically significant bias. It will be tested early next year and will be subject to further assessment.

“Our priority is ensuring public safety. This gamechanging technology will assist officers to apprehend and prosecute offenders. There is officer review in every step of the process and no arrest or charge would be taken without specialist personnel carefully reviewing the results.”