British Law Enforcement Agencies Lobbied to Use Biased Facial Recognition Technology

Law enforcement agencies across the UK successfully lobbied to use a face scanning system known to be biased against females, youths, and members of minority ethnic backgrounds, following complaints that a more accurate version generated fewer potential suspects.

How the System Works

UK forces utilize the national police database to carry out retrospective facial recognition searches. This process involves matching a reference photograph of a person of interest against a repository of more than 19 million mugshots to find potential matches.

Acknowledged Discrimination

The Home Office conceded last week that the technology was flawed. This acknowledgment followed a review by the government's National Physical Laboratory found it incorrectly matched people of Black and Asian heritage and women at much greater frequency than white men. The ministry said it “had acted on the findings”.

“It prompts the issue of whether this technology only becomes useful if users tolerate biases in ethnicity and gender. Convenience is a weak argument for overriding basic freedoms.”

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 address the problem.

Senior officers were informed of the system's bias in late 2024. The Home Office-commissioned NPL review found the system was had a higher probability to produce incorrect matches for images depicting women, Black people, and those aged 40 and under.

A Reversed Decision

In reaction, the national police leadership body mandated that the accuracy setting required for possible hits be raised to a point where the bias was greatly diminished.

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

Severe Disparities

Although the Home Office and NPCC declined to specify what setting is currently used, the recent NPL study discovered the system could generate false positives for Black women nearly a hundred times more often than for Caucasian women at certain settings.

The Home Office commented on these findings: “The testing found that in a limited set of circumstances the software 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 confidence threshold, the NPCC documents note: “The change greatly lessens the effect of discrimination across protected characteristics of race, age and gender but had a substantially detrimental effect on police efficiency”. The documents further note that police units complained that “a previously useful tool returned results of limited benefit”.

Wider Implementation Proposals

Meanwhile, the UK administration has launched a ten-week public review on its plans to expand the use of biometric scanning systems. Policing minister Sarah Jones has labeled the technology as the “most significant advance since DNA matching”.

Criticism from Advisors and Monitors

The chair of a police oversight board, head of the advisory panel for the national policing equality strategy, said: “We observed very little discussion through equality strategy sessions of the facial recognition rollout even with clear relevance with the strategy's goals.

“This disclosure demonstrate yet again that the pledges to combat discrimination the police has made via the equality initiative are failing to be integrated into wider practice. Our reports have warned that innovative tools are being implemented in a landscape where racial disparities, weak scrutiny and faulty information gathering continue to exist.

“Any use of facial recognition must meet strict national standards, be subject to external review, and demonstrate it diminishes rather than compounds racial disparity.”

Official Statement

A government representative said: “The Home Office treat the conclusions of the report seriously and we have already taken action. A new algorithm has been externally evaluated and acquired, which has demonstrated no measurable discrimination. It will be tested early next year and will be subject to further assessment.

“Our priority is protecting the public. This revolutionary tool will assist police to apprehend and prosecute offenders. There is human involvement in every step of the process and no arrest or charge would be taken without specialist personnel meticulously examining the output.”