Law enforcement agencies across the UK effectively campaigned to use a facial recognition system known to be discriminatory against females, young people, and individuals from ethnic minority groups, after complaining that a less biased version generated fewer investigative leads.
How the System Works
UK forces utilize the national police database to conduct retrospective facial recognition searches. This process entails matching a “probe image” of a person of interest against a repository of over 19 million mugshots to find possible hits.
Admitted Bias
The UK interior ministry admitted last week that the system was biased. This acknowledgment followed a study by the government's National Physical Laboratory determined it incorrectly matched people of Black and Asian heritage and women at significantly higher rates than Caucasian males. The ministry said it “took steps on the findings”.
“It prompts the issue of whether facial recognition only becomes useful if users accept discrimination in ethnicity and gender. Convenience is a poor argument for overriding fundamental rights.”
Long-Standing Problem
Official papers show that this bias has been known about for over twelve months. Furthermore, police forces argued to overturn an earlier ruling that was intended to address the problem.
Police bosses were informed of the system's bias in late 2024. The government-ordered laboratory study concluded the system was more likely to produce false positives for photos of women, Black people, and those under 40 years old.
A Reversed Decision
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 adjusted system was generating fewer “useful lines of inquiry”. Internal records indicate the stricter setting cut the proportion of searches that yielded possible identifications from over half to a mere 14%.
Severe Disparities
Although the authorities declined to specify what threshold is now in operation, the latest independent review found the system could produce false positives for Black women nearly a hundred times more frequently than for white women at specific configurations.
The Home Office commented on these results: “The testing found that in a limited set of circumstances the algorithm is has a greater tendency to incorrectly include some population segments in its match reports.”
Balancing Utility and Fairness
Describing the impact of the brief increase to the system's accuracy setting, the police records state: “This adjustment greatly lessens the impact of discrimination across protected characteristics of ethnicity, generation and sex but had a significant negative impact on police efficiency”. The documents further note that forces argued that “a previously useful tool now delivered results of limited benefit”.
Broader Rollout Plans
Meanwhile, the government has opened a two-and-a-half-month consultation on its proposals to widen the use of biometric scanning systems. The minister for police Sarah Jones has labeled the technology as the “most significant advance 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, said: “There was very little consideration through equality strategy sessions of the technology deployment despite clear relevance with the strategy's goals.
“This disclosure show once again that the anti-racism commitments the police has made through the equality initiative are failing to be integrated into broader operations. Our reports have warned that new technologies are being implemented in a context where ethnic inequalities, inadequate oversight and poor data collection already persist.
“Any use of facial recognition must adhere to strict national standards, be independently scrutinised, and demonstrate it reduces rather than exacerbates ethnic bias.”
Home Office Response
A Home Office spokesperson said: “The Home Office takes 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 no statistically significant bias. It will be trialled in the coming months and will be undergo further assessment.
“The foremost aim is protecting the public. This gamechanging technology will assist police to apprehend and prosecute offenders. There is human involvement in each stage of the process and no further action would be pursued without trained officers carefully reviewing the output.”
