British Law Enforcement Agencies Lobbied to Use Biased Facial Recognition Technology

Police forces across the United Kingdom successfully lobbied to use a face scanning system known to be biased against women, young people, and individuals from ethnic minority groups, following complaints that a more accurate version generated a reduced number of investigative leads.

The Technology in Practice

British police use the police national database (PND) to carry out retrospective facial recognition searches. This process entails comparing a “probe image” of a suspect against a database of over 19 million custody photos to identify potential matches.

Acknowledged Discrimination

The UK interior ministry conceded last week that the technology was biased. This acknowledgment came after a review by the government's National Physical Laboratory found it incorrectly matched Black and Asian people and females at significantly higher rates than Caucasian males. The ministry said 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 poor argument for disregarding basic freedoms.”

Long-Standing Problem

Official papers show that this bias has been recognized for more than a year. Furthermore, law enforcement lobbied to reverse an initial decision that was designed to address the problem.

Senior officers were informed of the system's bias in September 2024. The Home Office-commissioned laboratory study concluded the system was had a higher probability to produce false positives for photos of women, Black people, and those aged 40 and under.

A Reversed Decision

In response, the national police leadership body ordered that the accuracy setting required for potential matches be raised to a level where the bias was greatly diminished.

However, this directive was reversed the next month following complaints from police that the adjusted system was producing fewer “investigative leads”. NPCC documents indicate the higher threshold reduced the number of searches that yielded possible identifications from 56% to a just 14%.

Profound Inequalities

Although the authorities refused to say what setting is currently used, the recent NPL study discovered the system could generate false positives for Black women nearly a hundred times more frequently than for Caucasian women at certain settings.

The ministry commented on these findings: “Our evaluation found that in a specific scenarios the software is more likely to incorrectly include some demographic groups in its match reports.”

Balancing Utility and Fairness

Describing the effect of the brief increase to the system's accuracy setting, the NPCC documents note: “The change significantly reduces the effect of discrimination across protected characteristics of ethnicity, age and gender but had a significant negative impact on police efficiency”. The documents further note that forces complained that “a previously useful tool returned results of limited benefit”.

Broader Rollout Plans

Meanwhile, the government has opened a two-and-a-half-month public review on its proposals to widen the use of facial recognition technology. Policing minister Sarah Jones has described the technology as the “most significant advance since DNA matching”.

Expert and Oversight Concerns

Abimbola Johnson, chair of the advisory panel for the police race action plan, commented: “We observed very little discussion through equality strategy sessions of the technology deployment despite obvious cross-over with the plan’s concerns.

“These revelations demonstrate yet again that the pledges to combat discrimination the police has undertaken through the race action plan are failing to be integrated into wider practice. Our reports have cautioned that innovative tools are being implemented in a context where ethnic inequalities, weak scrutiny and faulty information gathering already persist.

“All deployment of this technology must adhere to strict national standards, be independently scrutinised, and demonstrate it reduces rather than exacerbates ethnic bias.”

Official Statement

A government representative stated: “The Home Office treat the conclusions of the study seriously and we have implemented changes. A updated software has been independently tested and procured, which has no statistically significant bias. It will be tested in the coming months and will be subject to evaluation.

“Our priority is ensuring public safety. This revolutionary tool will assist officers to apprehend and prosecute offenders. There is officer review in each stage of the procedure and no arrest or charge would be taken without trained officers meticulously examining the results.”