British Police Forces Lobbied to Employ Biased Facial Recognition Technology

Law enforcement agencies across the UK successfully lobbied to deploy a face scanning system known to be discriminatory against females, young people, and individuals from ethnic minority groups, after complaining that a less biased version generated a reduced number of potential suspects.

The Technology in Practice

UK forces use the national police database to conduct retrospective facial recognition searches. This process involves comparing a reference photograph of a suspect against a repository of more than 19 million custody photos to find potential matches.

Acknowledged Discrimination

The UK interior ministry conceded last week that the technology was biased. This acknowledgment followed a study by the government's National Physical Laboratory found it incorrectly matched people of Black and Asian heritage and females at much greater frequency than white men. The Home Office said it “took steps on the findings”.

“It prompts the issue of whether facial recognition only becomes effective if users tolerate biases in race and sex. Convenience is a poor argument for overriding fundamental rights.”

Long-Standing Problem

Official papers reveal that this discriminatory flaw has been recognized for over twelve months. Furthermore, law enforcement argued to overturn an earlier ruling that was designed to address the problem.

Senior officers were informed of the algorithmic discrimination in late 2024. The government-ordered laboratory study found the system was had a higher probability to suggest false positives for photos of females, Black people, and those under 40 years old.

A Reversed Decision

In reaction, the national police leadership body ordered that the confidence threshold required for possible hits be increased to a point where the bias was greatly diminished.

However, this decision was overturned the following month following complaints from police that the modified technology was producing a lower number of “investigative leads”. Internal records show the stricter setting reduced the proportion of queries that yielded potential matches from 56% to a mere 14%.

Profound Inequalities

Although the authorities refused to say what threshold is now in operation, the recent independent review discovered the system could produce incorrect matches for women of Black heritage almost 100 times more often than for white women at specific configurations.

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

Balancing Utility and Fairness

Describing the effect of the temporary raise to the system's confidence threshold, the NPCC documents note: “This adjustment significantly reduces the effect of discrimination across protected characteristics of race, age and sex but had a substantially detrimental effect on operational effectiveness”. The papers add that forces argued that “a once effective tactic now delivered results of questionable value”.

Wider Implementation Proposals

Meanwhile, the UK administration has launched a ten-week consultation on its proposals to widen the use of facial recognition technology. Policing minister the relevant minister has described the technology as the “most significant advance since genetic fingerprinting”.

Criticism from Advisors and Monitors

Abimbola Johnson, chair of the advisory panel for the national policing equality strategy, said: “There was very little discussion in equality strategy sessions of the technology deployment despite clear relevance with the plan’s concerns.

“These revelations demonstrate once again that the anti-racism commitments policing has undertaken through the race action plan are failing to be integrated into wider practice. Independent assessments have cautioned that innovative tools are being implemented in a context 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 demonstrate it reduces rather than compounds ethnic bias.”

Official Statement

A government representative stated: “The Home Office treat the conclusions of the report seriously and we have implemented changes. A new algorithm has been independently tested and acquired, which has demonstrated no measurable discrimination. It will be tested in the coming months and will be subject to further assessment.

“Our priority is protecting the public. This revolutionary tool will support police to apprehend and prosecute offenders. There is human involvement in every step of the procedure and no further action would be pursued without specialist personnel meticulously examining the output.”