British Police Forces Lobbied to Use Discriminatory Facial Recognition Systems
Law enforcement agencies across the UK successfully lobbied to deploy a face scanning system acknowledged as discriminatory against women, youths, and individuals from minority ethnic backgrounds, following complaints that a less biased version produced a reduced number of investigative leads.
The Technology in Practice
UK forces utilize the national police database to carry out retrospective facial recognition searches. This procedure entails matching a reference photograph of a person of interest against a database of over 19 million custody photos to find possible hits.
Admitted Bias
The UK interior ministry admitted last week that the technology was flawed. This acknowledgment followed a review by the National Physical Laboratory (NPL) found it misidentified Black and Asian people and women at much greater frequency than white men. The ministry stated it “had acted on the findings”.
“This raises the question of whether this technology only becomes useful if users tolerate biases in ethnicity and gender. Convenience is a poor argument for overriding basic freedoms.”
Known Issue
Official papers show that this bias has been known about for over twelve months. Furthermore, police forces lobbied to reverse an earlier ruling that was designed to address the problem.
Police bosses were informed of the system's bias in late 2024. The government-ordered NPL review found the system was had a higher probability to produce false positives for images depicting women, Black people, and those aged 40 and under.
A Reversed Decision
In reaction, the national police leadership body ordered that the confidence threshold required for potential matches be raised to a level where the disparity was significantly reduced.
However, this directive was overturned the next month after forces complained that the adjusted system was generating a lower number of “investigative leads”. Internal records indicate the higher threshold cut the number of queries that yielded potential matches from over half to a mere under 15%.
Profound Inequalities
Although the authorities refused to say what setting is currently used, the recent NPL study discovered the system could generate false positives for women of Black heritage nearly a hundred times more often than for Caucasian women at specific configurations.
The Home Office stated on these findings: “The testing identified that in a limited set of circumstances the algorithm is has a greater tendency to wrongly flag 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 NPCC documents note: “The change greatly lessens the impact of discrimination across legally safeguarded attributes of ethnicity, generation and gender but had a significant negative impact on police efficiency”. The documents further note that police units argued that “a once effective tactic returned outcomes of limited benefit”.
Wider Implementation Proposals
Meanwhile, the government has launched a ten-week public review on its proposals to expand the use of biometric scanning systems. Policing minister Sarah Jones has labeled the technology as the “most significant advance since genetic fingerprinting”.
Criticism from Advisors and Monitors
Abimbola Johnson, chair of the independent scrutiny and oversight board for the police race action plan, commented: “We observed very little discussion in equality strategy sessions of the facial recognition rollout even with obvious cross-over with the plan’s concerns.
“This disclosure show yet again that the pledges to combat discrimination policing has undertaken through the race action plan are not being translated into wider practice. Our reports have cautioned that innovative tools are being rolled out in a landscape where ethnic inequalities, inadequate oversight and faulty information gathering already persist.
“All deployment of this technology must meet strict national standards, be independently scrutinised, and demonstrate it diminishes rather than exacerbates racial disparity.”
Home Office Response
A Home Office spokesperson stated: “The Home Office treat the findings of the report with utmost gravity and we have implemented changes. A new algorithm has been externally evaluated and acquired, which has no statistically significant bias. It will be tested in the coming months and will be undergo further assessment.
“Our priority is ensuring public safety. This gamechanging technology will support police to apprehend and prosecute offenders. There is human involvement in each stage of the process and no arrest or charge would be pursued without trained officers carefully reviewing the results.”
