UK Police Forces Lobbied to Use Discriminatory Facial Recognition Systems

Law enforcement agencies across the United Kingdom effectively campaigned to use a face scanning system acknowledged as biased against women, youths, and members of minority ethnic backgrounds, after complaining that a more accurate version generated fewer potential suspects.

How the System Works

British police utilize the national police database to carry out retrospective facial recognition searches. This process involves comparing a reference photograph of a suspect against a repository of over 19 million custody photos to find possible hits.

Acknowledged Discrimination

The UK interior ministry admitted last week that the technology was flawed. This admission came after 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 said it “had acted on the findings”.

“This raises the question of whether this technology only becomes effective if users tolerate biases in ethnicity and sex. Convenience is a poor argument for overriding fundamental rights.”

Long-Standing Problem

Internal documents reveal that this discriminatory flaw has been recognized for over twelve months. Furthermore, law enforcement argued to overturn an earlier ruling that was intended to address the problem.

Senior officers were informed of the system's bias in late 2024. The government-ordered NPL review found the system was more likely to produce false positives for images depicting women, individuals of Black ethnicity, and those aged 40 and under.

A Policy U-Turn

In reaction, the national police leadership body ordered that the accuracy setting required for possible hits be increased to a point where the disparity was greatly diminished.

However, this decision was overturned the next month following complaints from police that the modified technology was generating a lower number of “investigative leads”. NPCC documents indicate the higher threshold cut the proportion of queries that yielded possible identifications from 56% to a just 14%.

Severe Disparities

Although the authorities refused to say what threshold is now in operation, the recent independent review found the system could generate incorrect matches for Black women almost 100 times more frequently than for white women at specific configurations.

The ministry commented on these results: “The testing identified that in a specific scenarios the software is more likely to wrongly flag some demographic groups in its match reports.”

Operational Effectiveness vs. Bias

Describing the effect of the temporary raise to the system's confidence threshold, the NPCC documents note: “This adjustment greatly lessens the impact of bias across protected characteristics of ethnicity, generation and gender but had a significant negative impact on police efficiency”. The documents add that forces argued that “a previously useful tool now delivered outcomes of questionable value”.

Broader Rollout Plans

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

Expert and Oversight Concerns

Abimbola Johnson, chair of the independent scrutiny and oversight board for the national policing equality strategy, said: “There was scant consideration through race action plan meetings of the facial recognition rollout despite obvious cross-over with the plan’s concerns.

“These revelations show once again that the anti-racism commitments policing has undertaken via the race action plan are failing to be integrated into broader operations. Our reports have cautioned that new technologies are being rolled out in a context where racial disparities, inadequate oversight and poor data collection continue to exist.

“All deployment of facial recognition must meet strict national standards, be subject to external review, and demonstrate it diminishes rather than exacerbates racial disparity.”

Official Statement

A Home Office spokesperson said: “The Home Office takes the findings of the study seriously and we have implemented changes. A updated software has been independently tested and acquired, which has demonstrated no measurable discrimination. It will be trialled early next year and will be undergo evaluation.

“The foremost aim is protecting the public. This revolutionary tool will assist officers to apprehend and prosecute offenders. There is officer review in every step of the process and no arrest or charge would be pursued without specialist personnel meticulously examining the results.”