🔗 Share this article

Law enforcement agencies across the UK successfully lobbied to deploy a facial recognition system acknowledged as discriminatory against females, young people, and members of minority ethnic backgrounds, after complaining that a more accurate version generated 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 matching a reference photograph of a suspect against a repository of more than 19 million custody photos to identify possible hits.

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 found it misidentified people of Black and Asian heritage and females at much greater frequency than white men. The ministry said it “took steps on the findings”.

“It prompts the issue of whether facial recognition only becomes useful if users accept biases in ethnicity and sex. Convenience is a weak argument for overriding fundamental rights.”

Known Issue

Official papers reveal that this bias has been known about for more than a year. Furthermore, police forces argued to overturn an earlier ruling that was intended to mitigate the problem.

Senior officers were informed of the algorithmic discrimination in late 2024. The Home Office-commissioned laboratory study concluded the system was had a higher probability to suggest incorrect matches for images depicting women, individuals of Black ethnicity, and those under 40 years old.

A Reversed Decision

In reaction, the national police leadership body mandated that the accuracy setting required for potential matches be increased to a point where the disparity was greatly diminished.

However, this directive was reversed the following month after forces complained that the adjusted system was producing a lower number of “useful lines of inquiry”. Internal records indicate the stricter setting cut the proportion of queries resulting in potential matches from 56% to a just 14%.

Profound Inequalities

Although the Home Office and NPCC declined to specify what setting is currently used, the latest independent review found the system could produce false positives for Black women almost 100 times more often than for white women at certain settings.

The ministry commented on these findings: “Our evaluation found that in a limited set of circumstances the algorithm is more likely to wrongly flag some demographic groups in its match reports.”

Operational Effectiveness vs. Bias

Outlining the effect of the temporary raise to the system's accuracy setting, the police records state: “This adjustment significantly reduces the effect of bias across protected characteristics of race, generation and gender but had a substantially detrimental effect on operational effectiveness”. The papers further note that police units complained that “a once effective tactic returned outcomes of limited benefit”.

Broader Rollout Plans

Meanwhile, the UK administration has opened a two-and-a-half-month public review on its proposals to expand the use of biometric scanning systems. The minister for police the relevant minister has labeled the technology as the “most significant advance since DNA matching”.

Criticism from Advisors and Monitors

Abimbola Johnson, chair of the advisory panel for the police race action plan, commented: “We observed very little consideration in equality strategy sessions of the technology deployment even with obvious cross-over with the strategy's goals.

“This disclosure demonstrate yet again that the anti-racism commitments the police has undertaken via the race action plan are failing to be integrated into wider practice. Our reports have cautioned that innovative tools are being implemented in a landscape where ethnic inequalities, inadequate oversight and faulty information gathering continue to exist.

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

Official Statement

A government representative said: “The Home Office takes the conclusions of the report seriously and we have already taken action. A new algorithm has been independently tested and procured, which has demonstrated no measurable discrimination. It will be trialled in the coming months and will be undergo further assessment.

“The foremost aim is ensuring public safety. This gamechanging technology will support officers to apprehend and prosecute offenders. There is human involvement in each stage of the procedure and no further action would be taken without specialist personnel meticulously examining the results.”