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Law enforcement agencies across the UK effectively campaigned to deploy a facial recognition system acknowledged as biased against women, youths, and individuals from minority ethnic backgrounds, following complaints that a more accurate version generated a reduced number of investigative leads.

The Technology in Practice

UK forces use the police national database (PND) to carry out searches using historical face recognition. This procedure involves matching a “probe image” of a person of interest against a repository of over 19 million custody photos to identify possible hits.

Admitted Bias

The UK interior ministry conceded last week that the technology was flawed. This acknowledgment came after a study by the government's National Physical Laboratory determined it incorrectly matched Black and Asian people and women at significantly higher rates than Caucasian males. The ministry stated it “had acted on the findings”.

“It prompts the question of whether facial recognition only becomes effective if users tolerate discrimination in ethnicity and sex. Convenience is a weak argument for overriding basic freedoms.”

Long-Standing Problem

Internal documents reveal that this discriminatory flaw has been known about for over twelve months. Furthermore, police forces 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 laboratory study found the system was had a higher probability to produce false positives for photos of females, Black people, and those aged 40 and under.

A Policy U-Turn

In reaction, the national police leadership body ordered that the confidence threshold required for potential matches be increased to a level where the disparity was significantly reduced.

However, this decision was reversed the next month following complaints from police that the adjusted system was generating fewer “investigative leads”. NPCC documents show the higher threshold reduced the number of searches resulting in possible identifications from 56% to a mere under 15%.

Profound Inequalities

Although the authorities refused to say what setting is currently used, the latest NPL study discovered the system could generate incorrect matches for Black women almost 100 times more often than for Caucasian women at specific configurations.

The Home Office commented on these findings: “The testing identified that in a limited set of circumstances the software is more likely to incorrectly include some demographic groups in its match reports.”

Operational Effectiveness vs. Bias

Describing the impact of the brief increase to the system's confidence threshold, the NPCC documents note: “The change significantly reduces the effect of discrimination across legally safeguarded attributes of ethnicity, generation and gender but had a significant negative impact on operational effectiveness”. The papers add that police units complained that “a once effective tactic now delivered outcomes of questionable value”.

Broader Rollout Plans

Meanwhile, the UK administration has launched a two-and-a-half-month consultation on its proposals to expand the use of facial recognition technology. The minister for police the relevant minister has labeled the technology as the “most significant advance since genetic fingerprinting”.

Expert and Oversight Concerns

The chair of a police oversight board, head of the advisory panel for the national policing equality strategy, said: “We observed scant discussion in equality strategy sessions of the facial recognition rollout despite obvious cross-over with the strategy's goals.

“This disclosure show once again that the anti-racism commitments the police has made via the equality initiative are failing to be integrated into broader operations. Our reports have cautioned that new technologies are being implemented in a landscape 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 racial disparity.”

Official Statement

A government representative said: “The Home Office takes the findings of the report seriously and we have implemented changes. A updated software has been externally evaluated and procured, which has demonstrated no measurable discrimination. It will be trialled in the coming months and will be subject to evaluation.

“The foremost aim is ensuring public safety. This gamechanging technology will support 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 carefully reviewing the output.”