🔗 Share this article

Law enforcement agencies across the United Kingdom effectively campaigned to deploy a facial recognition system known to be biased against women, young people, and individuals from minority ethnic backgrounds, after complaining that a more accurate version produced fewer investigative leads.

How the System Works

British police use the national police database to conduct searches using historical face recognition. This procedure entails matching a reference photograph of a suspect against a database of over 19 million custody photos to find potential matches.

Admitted Bias

The Home Office conceded last week that the system was flawed. This acknowledgment came after a study by the National Physical Laboratory (NPL) determined it misidentified people of Black and Asian heritage and women at much greater frequency than Caucasian males. The Home Office stated it “had acted on the findings”.

“This raises the question of whether this technology only becomes useful if users accept discrimination in ethnicity and sex. Operational ease is a poor argument for disregarding basic freedoms.”

Known Issue

Internal documents show that this discriminatory flaw has been recognized for more than a year. Furthermore, police forces lobbied to reverse an initial decision that was designed to address the problem.

Police bosses were notified of the algorithmic discrimination in September 2024. The Home Office-commissioned laboratory study concluded the system was had a higher probability to produce false positives for photos of women, individuals of Black ethnicity, and those aged 40 and under.

A Reversed Decision

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

However, this decision was overturned the next month following complaints from police that the adjusted system was generating fewer “investigative leads”. Internal records indicate the higher threshold reduced the number of queries that yielded potential matches from 56% to a just under 15%.

Profound Inequalities

Although the Home Office and NPCC refused to say what threshold is currently used, the latest NPL study discovered the system could produce incorrect matches for women of Black heritage nearly a hundred times more frequently than for Caucasian women at certain settings.

The Home Office stated on these findings: “The testing identified that in a limited set of circumstances the software is has a greater tendency to incorrectly include some demographic groups in its match reports.”

Balancing Utility and Fairness

Describing the effect of the temporary raise to the system's accuracy setting, the police records note: “The change significantly reduces the impact of discrimination across protected characteristics of race, age and sex but had a significant negative impact on police efficiency”. The papers add that police units argued that “a once effective tactic now delivered results of questionable value”.

Wider Implementation Proposals

Meanwhile, the UK administration has launched a ten-week public review on its proposals to widen the use of facial recognition technology. Policing minister Sarah Jones has described the technology as the “most significant advance since genetic fingerprinting”.

Expert and Oversight Concerns

Abimbola Johnson, head of the independent scrutiny and oversight board for the national policing equality strategy, commented: “There was scant consideration in race action plan meetings of the facial recognition rollout despite obvious cross-over with the strategy's goals.

“This disclosure demonstrate yet again that the anti-racism commitments policing has made through the equality initiative are failing to be integrated into wider practice. Our reports have warned that new technologies are being implemented in a context where racial disparities, weak scrutiny and poor data collection already persist.

“Any use of facial recognition must adhere to rigorous official guidelines, be subject to external review, and demonstrate it reduces rather than exacerbates racial disparity.”

Official Statement

A government representative said: “The Home Office treat the findings of the report seriously and we have implemented changes. A updated software has been independently tested and acquired, which has no statistically significant bias. It will be tested in the coming months and will be subject to evaluation.

“The foremost aim is ensuring public safety. This gamechanging technology will assist police to apprehend and prosecute offenders. There is human involvement in every step of the procedure and no arrest or charge would be taken without trained officers meticulously examining the output.”