British Law Enforcement Agencies Lobbied to Employ Biased Face Scanning Technology

Police forces across the United Kingdom successfully lobbied to deploy a face scanning system acknowledged as discriminatory against women, youths, and individuals from ethnic minority groups, after complaining that a less biased version produced fewer potential suspects.

The Technology in Practice

British police utilize the police national database (PND) to conduct searches using historical face recognition. This procedure involves matching a reference photograph of a suspect against a repository of over 19 million custody photos to find potential matches.

Acknowledged Discrimination

The UK interior ministry admitted last week that the technology was biased. This acknowledgment came after a review by the government's National Physical Laboratory determined it misidentified people of Black and Asian heritage and women at much greater frequency than white men. The Home Office stated it “took steps on the findings”.

“This raises the issue of whether facial recognition only becomes useful if users tolerate biases in race and gender. Operational ease is a weak argument for disregarding basic freedoms.”

Known Issue

Internal documents show that this bias 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 informed of the system's bias in September 2024. The Home Office-commissioned laboratory study concluded the system was had a higher probability to produce incorrect matches for images depicting women, Black people, and those aged 40 and under.

A Reversed Decision

In response, the National Police Chiefs’ Council (NPCC) mandated that the accuracy setting required for possible hits be raised to a level where the disparity was greatly diminished.

However, this decision was overturned the following month after forces complained that the adjusted system was producing a lower number of “useful lines of inquiry”. Internal records show the stricter setting cut the number of queries resulting in possible identifications from 56% to a mere 14%.

Profound Inequalities

Although the authorities refused to say what threshold is now in operation, the latest NPL study discovered the system could produce incorrect matches for Black women nearly a hundred times more frequently than for Caucasian women at certain settings.

The Home Office stated on these results: “The testing found that in a limited set of circumstances the software is more likely to wrongly flag some population segments in its search results.”

Operational Effectiveness vs. Bias

Outlining the effect of the temporary raise to the system's confidence threshold, the NPCC documents state: “The change significantly reduces the effect of discrimination across legally safeguarded attributes of ethnicity, age and sex but had a significant negative impact on operational effectiveness”. The papers add that forces argued that “a once effective tactic now delivered results of questionable value”.

Wider Implementation Proposals

Meanwhile, the government has launched a two-and-a-half-month public review on its plans 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

Abimbola Johnson, chair of the advisory panel for the police race action plan, said: “There was very little consideration through race action plan meetings of the technology deployment even with obvious cross-over with the strategy's goals.

“These revelations show yet again that the anti-racism commitments policing has undertaken through the race action plan are not being translated into wider practice. Independent assessments have warned that innovative tools are being implemented in a landscape where ethnic inequalities, inadequate oversight and poor data collection already persist.

“Any use of facial recognition must adhere to rigorous official guidelines, be independently scrutinised, and prove it diminishes rather than exacerbates racial disparity.”

Official Statement

A government representative said: “The Home Office treat the findings of the report seriously and we have already taken action. A updated software has been externally evaluated and procured, which has demonstrated no measurable discrimination. It will be trialled in the coming months and will be undergo evaluation.

“Our priority is protecting the public. This gamechanging technology will support officers to apprehend and prosecute offenders. There is human involvement in each stage of the process and no arrest or charge would be taken without specialist personnel meticulously examining the results.”