🔗 Share this article

Law enforcement agencies across the UK effectively campaigned to use a facial recognition system known to be discriminatory against females, youths, and members of ethnic minority groups, after complaining that a less biased version produced fewer investigative leads.

How the System Works

UK forces utilize the police national database (PND) to conduct searches using historical face recognition. This process involves matching a reference photograph of a person of interest against a repository of more than 19 million custody photos to find potential matches.

Acknowledged Discrimination

The UK interior ministry admitted last week that the technology was flawed. This acknowledgment followed a study by the National Physical Laboratory (NPL) found it misidentified Black and Asian people and females at much greater frequency than Caucasian males. The ministry stated it “took steps on the findings”.

“It prompts the question of whether facial recognition only becomes useful if users accept discrimination in ethnicity and sex. Convenience is a poor argument for disregarding basic freedoms.”

Long-Standing Problem

Internal documents reveal that this discriminatory flaw has been recognized for more than a year. Furthermore, law enforcement argued to overturn an earlier ruling that was intended to mitigate the problem.

Police bosses were informed of the algorithmic discrimination in late 2024. The government-ordered laboratory study found the system was more likely to produce incorrect matches for images depicting females, Black people, and those under 40 years old.

A Reversed Decision

In reaction, the national police leadership body mandated that the confidence threshold required for possible hits be increased to a level where the bias was greatly diminished.

However, this directive was reversed the following month following complaints from police that the modified technology was generating fewer “useful lines of inquiry”. Internal records indicate the stricter setting cut the number of searches resulting in possible identifications from 56% to a mere 14%.

Severe Disparities

Although the authorities declined to specify what threshold is currently used, the latest independent review discovered the system could produce false positives for women of Black heritage almost 100 times more often than for Caucasian women at certain settings.

The ministry commented on these findings: “Our evaluation found that in a limited set of circumstances the algorithm is has a greater tendency to incorrectly include some demographic groups in its search results.”

Balancing Utility and Fairness

Describing the effect of the brief increase to the system's accuracy setting, the NPCC documents state: “This adjustment significantly reduces the effect of discrimination across protected characteristics of ethnicity, age and sex but had a substantially detrimental effect on police efficiency”. The papers add that forces argued that “a previously useful tool returned results of questionable value”.

Wider Implementation Proposals

Meanwhile, the government has launched a ten-week consultation on its proposals to expand the use of biometric scanning systems. Policing minister Sarah Jones has labeled the tool as the “most significant advance since DNA matching”.

Criticism from Advisors and Monitors

The chair of a police oversight board, chair of the independent scrutiny and oversight board for the police race action plan, commented: “There was scant consideration through race action plan meetings of the technology deployment despite clear relevance with the strategy's goals.

“This disclosure demonstrate yet again that the anti-racism commitments policing has undertaken through the race action plan are not being translated into wider practice. Our reports have cautioned that innovative tools are being implemented in a landscape where racial disparities, weak scrutiny and poor data collection continue to exist.

“All deployment of facial recognition must adhere to rigorous official guidelines, be subject to external review, and prove it reduces rather than exacerbates ethnic bias.”

Home Office Response

A government representative said: “We treat the conclusions of the study with utmost gravity and we have implemented changes. A updated software 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 assist police to apprehend and prosecute offenders. There is officer review in every step of the procedure and no arrest or charge would be pursued without trained officers meticulously examining the output.”