British Law Enforcement Agencies Campaign to Employ Biased Face Scanning Systems

Law enforcement agencies across the UK successfully lobbied to deploy a face scanning system acknowledged as biased against women, youths, and members of ethnic minority groups, following complaints that a more accurate version produced fewer investigative leads.

How the System Works

UK forces use the national police database to carry out searches using historical face recognition. This process involves matching a “probe image” of a suspect against a repository of over 19 million custody photos to identify possible hits.

Acknowledged Discrimination

The UK interior ministry admitted last week that the system was flawed. This acknowledgment followed a study by the government's National Physical Laboratory found it incorrectly matched Black and Asian people and females at significantly higher rates than white men. The ministry said it “took steps on the findings”.

“This raises the question 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

Official papers reveal that this discriminatory flaw has been known about for more than a year. Furthermore, police forces lobbied to reverse an earlier ruling that was designed to address the problem.

Police bosses were informed of the algorithmic discrimination in September 2024. The government-ordered NPL review concluded the system was more likely to produce false positives for photos of females, Black people, and those under 40 years old.

A Reversed Decision

In response, the national police leadership body mandated that the confidence threshold required for possible hits be raised to a point where the disparity was greatly diminished.

However, this decision was overturned the following month after forces complained that the adjusted system was producing a lower number of “investigative leads”. NPCC documents show the higher threshold cut the proportion of queries that yielded possible identifications from 56% to a just 14%.

Severe Disparities

Although the Home Office and NPCC refused to say what threshold is now in operation, the latest independent review discovered the system could produce false positives for Black women almost 100 times more often than for Caucasian women at specific configurations.

The Home Office commented on these findings: “The testing identified that in a specific scenarios the algorithm is more likely to wrongly flag some population segments in its search results.”

Operational Effectiveness vs. Bias

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

Wider Implementation Proposals

Meanwhile, the government has launched a two-and-a-half-month public review on its proposals to expand the use of facial recognition technology. The minister for police 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 police race action plan, said: “We observed very little consideration in equality strategy sessions of the technology deployment even with obvious cross-over with the strategy's goals.

“This disclosure show yet again that the anti-racism commitments the police has made via the equality initiative are not being translated into broader operations. Our reports have cautioned that new technologies are being rolled out in a context where ethnic inequalities, inadequate oversight and poor data collection continue to exist.

“Any use of this technology must adhere to strict national standards, be independently scrutinised, and demonstrate it reduces rather than exacerbates ethnic bias.”

Official Statement

A Home Office spokesperson said: “The Home Office treat the findings of the report seriously and we have already taken action. A updated software has been independently tested and procured, which has demonstrated no measurable discrimination. It will be trialled in the coming months and will be subject to further assessment.

“The foremost aim is protecting the public. This gamechanging technology will support police to put criminals and rapists behind bars. There is officer review in each stage of the procedure and no arrest or charge would be taken without specialist personnel meticulously examining the output.”