Met Police Deploys Live Facial Recognition at Notting Hill Carnival Despite Bias Concerns
The Metropolitan Police deployed live facial recognition at Notting Hill carnival despite concerns about bias and an Equality and Human Rights Commission finding that such police use is unlawful. An independent expert challenged the force's claim that a recent study showed the system was bias-free, citing insufficient sample size and documented false positives among ethnic minorities.
What happened
The Metropolitan Police planned to deploy live facial recognition at Notting Hill carnival in west London at two sites on the approaches to the event. The force insisted on using the technology despite the Equality and Human Rights Commission saying police use of LFR is unlawful.
The Met claims to have reformed its use of live facial recognition following a 2023 study commissioned from the National Physical Laboratory and states the system is now bias-free. However, Prof Pete Fussey, who led the only independent academic review of police use of facial recognition, said the Met's claims about the absence of bias are not substantiated by the facts in the NPL report.
Reported impact
The NPL study found bias at a setting of 0.56 sensitivity. At a setting of 0.6, the system produced seven false positives, all of which were people from ethnic minorities flagged as wanted.
The Equality and Human Rights Commission has stated that police use of live facial recognition is unlawful.
Index analysis
The NPL study tested the system after 178,000 images were entered, with 400 volunteers providing approximately 4,000 recognition opportunities across crowds estimated at more than 130,000 people at five sites in London and Cardiff. Testing took place in sunny conditions for 34.5 hours, which Fussey said is shorter than testing in some other countries.
Fussey argued the sample size was too small to support the Met's claims of no statistically significant bias at a sensitivity setting of 0.6 or higher.
Governance controls
The Metropolitan Police commissioned a study from the National Physical Laboratory to test the system for bias and adjust sensitivity settings accordingly.
The Equality and Human Rights Commission has determined that police use of live facial recognition is unlawful.
Classification
Sources and evidence
This record was researched and written by the Index, based on the following original reporting.