UK Law Enforcement Agencies Campaign to Use Biased Facial Recognition Technology

Law enforcement agencies across the UK effectively campaigned to use a face scanning system known to be discriminatory against females, young people, and members of ethnic minority groups, following complaints that a more accurate version produced fewer investigative leads.

The Technology in Practice

British police use the national police database to conduct searches using historical face recognition. This procedure involves matching a “probe image” of a suspect against a database of more than 19 million custody photos to find potential matches.

Admitted Bias

The Home Office conceded last week that the technology was biased. This acknowledgment followed a study by the government's National Physical Laboratory found it incorrectly matched Black and Asian people and females at much greater frequency than white men. The Home Office stated it “took steps on the findings”.

“This raises the question of whether facial recognition only becomes effective if users tolerate biases in race and gender. Operational ease is a weak argument for overriding fundamental rights.”

Known Issue

Official papers reveal that this bias has been known about for over twelve months. Furthermore, law enforcement lobbied to reverse an initial decision that was intended to address the problem.

Police bosses were notified of the algorithmic discrimination in late 2024. The Home Office-commissioned laboratory study concluded the system was more likely to produce incorrect matches for photos of women, Black people, and those under 40 years old.

A Policy U-Turn

In response, the national police leadership body mandated that the accuracy setting required for potential matches be raised to a level where the bias was significantly reduced.

However, this directive was reversed the following month after forces complained that the modified technology was generating a lower number of “useful lines of inquiry”. NPCC documents indicate the stricter setting cut the proportion of searches resulting in possible identifications from 56% to a mere under 15%.

Profound Inequalities

Although the Home Office and NPCC declined to specify what threshold is now in operation, the recent NPL study found the system could produce incorrect matches for Black women nearly a hundred times more frequently than for white women at specific configurations.

The Home Office commented on these results: “Our evaluation found that in a specific scenarios the algorithm is has a greater tendency to wrongly flag some population segments in its match reports.”

Balancing Utility and Fairness

Describing 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 legally safeguarded attributes of ethnicity, generation and gender but had a substantially detrimental effect on operational effectiveness”. The papers add that forces complained that “a once effective tactic now delivered outcomes of limited benefit”.

Broader Rollout Plans

Meanwhile, the UK administration has launched a two-and-a-half-month public review on its plans to expand the use of facial recognition technology. Policing minister the relevant minister has described the tool as the “biggest breakthrough since genetic fingerprinting”.

Expert and Oversight Concerns

The chair of a police oversight board, chair of the advisory panel for the national policing equality strategy, said: “We observed very little discussion in equality strategy sessions of the technology deployment despite obvious cross-over with the plan’s concerns.

“This disclosure demonstrate yet again that the pledges to combat discrimination policing has made through the race action plan are not being translated into wider practice. Independent assessments have cautioned that innovative tools are being rolled out in a landscape where ethnic inequalities, inadequate oversight and poor data collection continue to exist.

“Any use of facial recognition must adhere to strict national standards, be independently scrutinised, and demonstrate it reduces rather than compounds ethnic bias.”

Official Statement

A government representative said: “The Home Office takes the conclusions of the study 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 trialled in the coming months and will be undergo further assessment.

“Our priority is protecting the public. This gamechanging technology will support police to apprehend and prosecute offenders. There is officer review in every step of the process and no arrest or charge would be taken without specialist personnel meticulously examining the output.”