British Police Forces Campaign to Employ Biased Face Scanning Technology

Law enforcement agencies across the UK effectively campaigned to use a face scanning system acknowledged as biased against women, young people, and individuals from ethnic minority groups, following complaints that a less biased version generated fewer investigative leads.

How the System Works

UK forces utilize the national police database to carry out retrospective facial recognition searches. This process entails comparing a reference photograph of a suspect against a database of more than 19 million mugshots to find possible hits.

Acknowledged Discrimination

The UK interior ministry conceded last week that the system was flawed. This acknowledgment came after a study by the government's National Physical Laboratory determined it incorrectly matched people of Black and Asian heritage and females at much greater frequency than Caucasian males. The ministry stated it “had acted on the findings”.

“This raises the issue of whether facial recognition only becomes useful if users accept discrimination in race and gender. Convenience is a poor argument for overriding basic freedoms.”

Long-Standing Problem

Internal documents reveal that this discriminatory flaw has been known about for more than a year. Furthermore, law enforcement argued to overturn an initial decision that was designed to address the problem.

Police bosses were notified of the system's bias in September 2024. The Home Office-commissioned laboratory study concluded the system was had a higher probability to suggest false positives for photos of women, individuals of Black ethnicity, 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 greatly diminished.

However, this directive was overturned the following month following complaints from police that the adjusted system was generating fewer “useful lines of inquiry”. Internal records indicate the higher threshold reduced the number of queries resulting in possible identifications from 56% to a mere 14%.

Profound Inequalities

Although the Home Office and NPCC refused to say what setting is currently used, the latest NPL study found the system could generate false positives for women of Black heritage nearly a hundred times more frequently than for white women at certain settings.

The ministry stated on these results: “Our evaluation identified that in a specific scenarios the software is more likely 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 confidence threshold, the police records state: “This adjustment greatly lessens the effect of bias across protected characteristics of ethnicity, generation and sex but had a substantially detrimental effect on operational effectiveness”. The documents further note that police units argued that “a previously useful tool returned outcomes of questionable value”.

Wider Implementation Proposals

Meanwhile, the UK administration has opened a ten-week public review on its proposals to widen the use of biometric scanning systems. The minister for police the relevant minister has labeled the tool as the “biggest breakthrough since DNA matching”.

Criticism from Advisors and Monitors

The chair of a police oversight board, head of the advisory panel for the national policing equality strategy, said: “We observed scant discussion in race action plan meetings of the technology deployment even with obvious cross-over with the plan’s concerns.

“These revelations demonstrate once again that the anti-racism commitments the police has made through the race action plan are not being translated into broader operations. Our reports 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 this technology must meet strict national standards, be independently scrutinised, and prove it reduces rather than compounds ethnic bias.”

Official Statement

A Home Office spokesperson said: “We treat the findings of the study seriously and we have implemented changes. A updated software has been externally evaluated and procured, which has demonstrated no measurable discrimination. It will be tested early next year and will be subject to further assessment.

“Our priority is protecting the public. This gamechanging technology will support officers to put criminals and rapists behind bars. There is officer review in every step of the process and no further action would be taken without specialist personnel carefully reviewing the output.”