Law enforcement agencies across the United Kingdom effectively campaigned to use a face scanning system known to be discriminatory against females, youths, and individuals from ethnic minority groups, following complaints that a more accurate version generated fewer investigative leads.
The Technology in Practice
UK forces use the police national database (PND) to conduct retrospective facial recognition searches. This process involves comparing a “probe image” of a person of interest against a repository of more than 19 million custody photos to find possible hits.
Acknowledged Discrimination
The Home Office admitted last week that the technology was flawed. This admission came after a review by the government's National Physical Laboratory found it misidentified people of Black and Asian heritage and women at much greater frequency than Caucasian males. The Home Office said it “took steps on the findings”.
“It prompts the issue of whether facial recognition only becomes effective if users accept biases in ethnicity and gender. Convenience is a poor argument for overriding basic freedoms.”
Long-Standing Problem
Official papers show that this discriminatory flaw has been recognized for over twelve months. Furthermore, law enforcement lobbied to reverse an earlier ruling that was intended to address the problem.
Senior officers were notified of the system's bias in late 2024. The government-ordered NPL review concluded the system was had a higher probability to produce incorrect matches for photos of females, individuals of Black ethnicity, and those aged 40 and under.
A Reversed Decision
In reaction, the National Police Chiefs’ Council (NPCC) mandated that the accuracy setting required for potential matches be raised to a point where the bias was greatly diminished.
However, this decision was reversed the following month following complaints from police that the adjusted system was generating a lower number of “useful lines of inquiry”. Internal records show the stricter setting cut the proportion of queries that yielded possible identifications from over half to a just 14%.
Severe Disparities
Although the Home Office and NPCC refused to say what setting is now in operation, the recent independent review found the system could produce false positives for Black women nearly a hundred times more frequently than for white women at certain settings.
The Home Office stated on these findings: “The testing found that in a specific scenarios the algorithm is has a greater tendency to wrongly flag some population segments in its search results.”
Operational Effectiveness vs. Bias
Describing the effect of the brief increase to the system's confidence threshold, the NPCC documents note: “This adjustment greatly lessens the impact of bias across legally safeguarded attributes of ethnicity, age and sex but had a substantially detrimental effect on operational effectiveness”. The papers further note that forces argued that “a once effective tactic now delivered outcomes of questionable value”.
Wider Implementation Proposals
Meanwhile, the UK administration has launched a ten-week consultation on its plans to widen the use of biometric scanning systems. Policing minister the relevant minister has labeled the tool as the “biggest breakthrough since genetic fingerprinting”.
Expert and Oversight Concerns
Abimbola Johnson, head of the independent scrutiny and oversight board for the police race action plan, commented: “There was scant discussion in race action plan meetings of the facial recognition rollout despite clear relevance with the strategy's goals.
“These revelations demonstrate once again that the pledges to combat discrimination policing has made via the race action plan are not being translated into wider practice. Our reports have cautioned that new technologies are being implemented in a landscape where racial disparities, inadequate oversight and poor data collection continue to exist.
“All deployment of facial recognition must adhere to strict national standards, be subject to external review, and prove it reduces rather than compounds racial disparity.”
Home Office Response
A government representative said: “We treat the conclusions of the report with utmost gravity and we have implemented changes. A updated software has been independently tested and procured, which has demonstrated no measurable discrimination. It will be tested in the coming months and will be undergo evaluation.
“Our priority is protecting the public. This gamechanging technology will assist police to apprehend and prosecute offenders. There is officer review in every step of the process and no further action would be taken without trained officers meticulously examining the results.”
