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Law enforcement agencies across the UK effectively campaigned to use a facial recognition system acknowledged as discriminatory against females, young people, and members of minority ethnic backgrounds, after complaining that a more accurate version produced fewer potential suspects.

How the System Works

British police utilize the police national database (PND) to conduct searches using historical face recognition. This process involves matching a “probe image” of a suspect against a repository of over 19 million custody photos to identify possible hits.

Acknowledged Discrimination

The Home Office conceded last week that the technology was flawed. This acknowledgment came after a study by the government's National Physical Laboratory found it incorrectly matched people of Black and Asian heritage and females at much greater frequency than Caucasian males. The Home Office stated it “took steps on the findings”.

“It prompts the question of whether this technology only becomes effective if users accept discrimination in ethnicity and sex. Convenience is a weak argument for disregarding basic freedoms.”

Known Issue

Official papers show that this discriminatory flaw has been known about for over twelve months. Furthermore, law enforcement argued to overturn an earlier ruling that was designed to mitigate the problem.

Senior officers were notified of the algorithmic discrimination in late 2024. The Home Office-commissioned NPL review found the system was had a higher probability to suggest false positives for images depicting females, individuals of Black ethnicity, and those under 40 years old.

A Policy U-Turn

In reaction, the National Police Chiefs’ Council (NPCC) ordered that the confidence threshold required for potential matches be increased to a point where the bias was significantly reduced.

However, this decision was overturned the following month following complaints from police that the modified technology was generating fewer “investigative leads”. NPCC documents show the higher threshold reduced the proportion of searches that yielded potential matches from 56% to a mere under 15%.

Profound Inequalities

Although the authorities declined to specify what setting is now in operation, the latest NPL study found the system could produce incorrect matches for women of Black heritage almost 100 times more often than for Caucasian women at certain settings.

The Home Office stated on these findings: “Our evaluation identified that in a specific scenarios the software is has a greater tendency to wrongly flag some demographic groups in its search results.”

Operational Effectiveness vs. Bias

Outlining the effect of the brief increase to the system's accuracy setting, the NPCC documents note: “The change greatly lessens the impact of discrimination across protected characteristics of race, generation and sex but had a substantially detrimental effect on police efficiency”. The papers add that police units argued that “a previously useful tool returned results of questionable value”.

Wider Implementation Proposals

Meanwhile, the UK administration has launched a two-and-a-half-month consultation on its proposals to widen the use of facial recognition technology. Policing minister Sarah Jones has labeled the tool as the “biggest breakthrough since genetic fingerprinting”.

Criticism from Advisors and Monitors

The chair of a police oversight board, head of the independent scrutiny and oversight board for the police race action plan, commented: “We observed scant discussion in equality strategy sessions of the facial recognition rollout even with obvious cross-over with the plan’s concerns.

“These revelations show once again that the anti-racism commitments the police has made via the equality initiative are not being translated into wider practice. Our reports have cautioned that new technologies are being implemented in a context where racial disparities, weak scrutiny and poor data collection continue to exist.

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

Official Statement

A government representative said: “We treat the conclusions of the report with utmost gravity and we have already taken action. A updated software has been independently tested and procured, which has demonstrated no measurable discrimination. It will be trialled in the coming months and will be subject to further assessment.

“Our priority is ensuring public safety. This gamechanging technology will support officers to apprehend and prosecute offenders. There is human involvement in every step of the procedure and no further action would be pursued without trained officers carefully reviewing the results.”