🔗 Share this article

Police forces across the United Kingdom effectively campaigned to use a facial recognition system acknowledged as discriminatory against females, youths, and members of minority ethnic backgrounds, following complaints that a less biased version generated fewer investigative leads.

How the System Works

British police use the police national database (PND) to conduct searches using historical face recognition. This procedure entails matching a reference photograph of a suspect against a repository of more than 19 million mugshots to identify possible hits.

Acknowledged Discrimination

The UK interior ministry admitted last week that the system was flawed. This admission followed a study by the National Physical Laboratory (NPL) found it incorrectly matched people of Black and Asian heritage and women at significantly higher rates than white men. The ministry said it “had acted on the findings”.

“This raises the issue of whether this technology only becomes useful if users accept discrimination in ethnicity and sex. Convenience is a weak argument for disregarding fundamental rights.”

Known Issue

Official papers show that this bias has been recognized for more than a year. Furthermore, police forces argued to overturn an initial decision that was designed to mitigate the problem.

Police bosses were informed of the algorithmic discrimination in September 2024. The government-ordered laboratory study found the system was had a higher probability to suggest false positives for photos of women, Black people, and those under 40 years old.

A Policy U-Turn

In response, the national police leadership body mandated that the accuracy setting required for potential matches be raised to a point where the bias was significantly reduced.

However, this decision was reversed the following month following complaints from police that the adjusted system was producing 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 now in operation, the recent independent review discovered the system could produce incorrect matches for women of Black heritage nearly a hundred times more often than for Caucasian women at certain settings.

The Home Office stated on these findings: “The testing identified that in a specific scenarios the software is has a greater tendency to incorrectly include some population segments in its match reports.”

Operational Effectiveness vs. Bias

Outlining the impact of the temporary raise to the system's confidence threshold, the NPCC documents note: “This adjustment greatly lessens the impact of bias across legally safeguarded attributes of race, generation and sex but had a substantially detrimental effect on police efficiency”. The papers further note that police units complained that “a previously useful tool returned results of limited benefit”.

Broader Rollout Plans

Meanwhile, the government has launched a two-and-a-half-month consultation on its proposals to expand the use of facial recognition technology. Policing minister the relevant minister has described the tool as the “biggest breakthrough since genetic fingerprinting”.

Expert and Oversight Concerns

Abimbola Johnson, head of the advisory panel for the national policing equality strategy, commented: “We observed scant consideration in race action plan meetings of the facial recognition rollout despite obvious cross-over with the plan’s concerns.

“This disclosure show once again that the anti-racism commitments policing has made via the equality initiative are failing to be integrated into broader operations. Our reports have cautioned that new technologies are being implemented in a context where ethnic inequalities, weak scrutiny and poor data collection continue to exist.

“All deployment of this technology must meet strict national standards, be independently scrutinised, and prove it reduces rather than exacerbates ethnic bias.”

Official Statement

A government representative said: “We treat the conclusions of the report seriously and we have already taken action. A new algorithm has been independently tested and acquired, which has demonstrated no measurable discrimination. It will be trialled in the coming months and will be subject to further assessment.

“Our priority is ensuring public safety. This gamechanging technology will support police to apprehend and prosecute offenders. There is officer review in every step of the process and no further action would be pursued without specialist personnel carefully reviewing the output.”