🔗 Share this article

Law enforcement agencies across the United Kingdom successfully lobbied to deploy a face scanning system acknowledged as biased against females, young people, and individuals from ethnic minority groups, following complaints that a more accurate version produced a reduced number of potential suspects.

How the System Works

British police use the national police database to carry out searches using historical face recognition. This process involves 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 admission followed a review by the government's National Physical Laboratory determined it incorrectly matched people of Black and Asian heritage and women at much greater frequency than white men. The ministry said it “took steps on the findings”.

“This raises the question of whether this technology only becomes useful if users accept discrimination in race and sex. Convenience is a weak argument for disregarding basic freedoms.”

Long-Standing Problem

Internal documents reveal that this bias has been recognized for over twelve months. Furthermore, law enforcement argued to overturn an earlier ruling that was intended to mitigate the problem.

Police bosses were notified of the algorithmic discrimination in September 2024. The government-ordered laboratory study concluded the system was had a higher probability to suggest false positives for images depicting females, individuals of Black ethnicity, and those aged 40 and under.

A Reversed Decision

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

However, this directive was reversed the following month after forces complained that the modified technology was producing fewer “investigative leads”. Internal records indicate the higher threshold cut the number of queries that yielded potential matches from 56% to a mere 14%.

Severe Disparities

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

The Home Office commented on these findings: “Our evaluation found that in a specific scenarios the software is has a greater tendency to incorrectly include some population segments in its match reports.”

Balancing Utility and Fairness

Describing the impact of the temporary raise to the system's accuracy setting, the police records state: “The change significantly reduces the impact of discrimination across protected characteristics of race, generation and sex but had a significant negative impact on police efficiency”. The documents add that police units complained that “a once effective tactic returned outcomes of questionable value”.

Broader Rollout Plans

Meanwhile, the government has launched a ten-week public review on its plans to expand the use of biometric scanning systems. The minister for police the relevant minister has labeled the technology as the “biggest breakthrough since genetic fingerprinting”.

Criticism from Advisors and Monitors

The chair of a police oversight board, chair of the advisory panel for the national policing equality strategy, commented: “We observed scant consideration through race action plan meetings of the technology deployment despite clear relevance with the plan’s concerns.

“This disclosure show yet again that the anti-racism commitments policing has undertaken via the equality initiative are failing to be integrated into wider practice. Our reports have cautioned that innovative tools are being rolled out in a context where ethnic inequalities, weak scrutiny and poor data collection already persist.

“Any use of this technology must adhere to rigorous official guidelines, be independently scrutinised, and prove it diminishes rather than exacerbates racial disparity.”

Official Statement

A government representative stated: “We takes the findings of the study seriously and we have implemented changes. A new algorithm has been externally evaluated and procured, which has demonstrated no measurable discrimination. It will be tested early next year and will be undergo further assessment.

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